diff --git a/.travis.yml b/.travis.yml
index 792f6a6195..a9f6bf3bfe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -105,7 +105,7 @@ install:
   # Conda-forge versioning is out of order (0.9.* is later than 2.12.*).
   - >
     if [[ "${TEST_MINIMAL}" != true ]]; then
-        conda install --quiet -n ${ENV_NAME} python-eccodes=0.9.3;
+        conda install --quiet -n ${ENV_NAME} python-eccodes">=0.9.1, <2";
         conda install --quiet -n ${ENV_NAME} --no-deps iris-grib;
     fi
 
@@ -162,13 +162,18 @@ script:
     fi
 
   # Split the organisation out of the slug. See https://stackoverflow.com/a/5257398/741316 for description.
-  - export ORG=(${TRAVIS_REPO_SLUG//\// })
+  # NOTE: a *separate* "export" command appears to be necessary here : A command of the
+  #   form "export ORG=.." failed to define ORG for the following command (?!)
+  - >
+    ORG=$(echo ${TRAVIS_REPO_SLUG} | cut -d/ -f1);
+    export ORG
+
+  - echo "Travis job context ORG=${ORG}; TRAVIS_EVENT_TYPE=${TRAVIS_EVENT_TYPE}; PUSH_BUILT_DOCS=${PUSH_BUILT_DOCS}"
 
   # When we merge a change to SciTools/iris, we can push docs to github pages.
   # At present, only the Python 3.7 "doctest" job does this.
   # Results appear at https://scitools-docs.github.io/iris/<<branchname>>/index.html
-  - >
-    if [[ "${ORG}" == 'SciTools' && "${TRAVIS_EVENT_TYPE}" == 'push' && "${PUSH_BUILT_DOCS}" == 'true' ]]; then
+  - if [[ "${ORG}" == 'SciTools' && "${TRAVIS_EVENT_TYPE}" == 'push' && "${PUSH_BUILT_DOCS}" == 'true' ]]; then
       cd ${INSTALL_DIR};
       pip install doctr;
       doctr deploy --deploy-repo SciTools-docs/iris --built-docs docs/iris/build/html
diff --git a/docs/iris/src/whatsnew/contributions_3.0.0/docchange_2019-Dec-04_black_code_formatting.txt b/docs/iris/src/whatsnew/contributions_3.0.0/docchange_2019-Dec-04_black_code_formatting.txt
new file mode 100644
index 0000000000..500a215bb9
--- /dev/null
+++ b/docs/iris/src/whatsnew/contributions_3.0.0/docchange_2019-Dec-04_black_code_formatting.txt
@@ -0,0 +1,6 @@
+* Added support for the `black <https://black.readthedocs.io/en/stable/>`_ code formatter.
+  This is now automatically checked on GitHub PRs, replacing the older, unittest-based
+  "iris.tests.test_coding_standards.TestCodeFormat".
+  Black provides automatic code format correction for most IDEs.
+  See the new developer guide section on this :
+  https://scitools-docs.github.io/iris/master/developers_guide/code_format.html.
diff --git a/lib/iris/experimental/regrid.py b/lib/iris/experimental/regrid.py
index 87d9e7e902..afbf87dee8 100644
--- a/lib/iris/experimental/regrid.py
+++ b/lib/iris/experimental/regrid.py
@@ -473,6 +473,24 @@ def _regrid_area_weighted_array(
         grid.
 
     """
+    # Determine which grid bounds are within src extent.
+    y_within_bounds = _within_bounds(
+        src_y_bounds, grid_y_bounds, grid_y_decreasing
+    )
+    x_within_bounds = _within_bounds(
+        src_x_bounds, grid_x_bounds, grid_x_decreasing
+    )
+
+    # Cache which src_bounds are within grid bounds
+    cached_x_bounds = []
+    cached_x_indices = []
+    for (x_0, x_1) in grid_x_bounds:
+        if grid_x_decreasing:
+            x_0, x_1 = x_1, x_0
+        x_bounds, x_indices = _cropped_bounds(src_x_bounds, x_0, x_1)
+        cached_x_bounds.append(x_bounds)
+        cached_x_indices.append(x_indices)
+
     # Create empty data array to match the new grid.
     # Note that dtype is not preserved and that the array is
     # masked to allow for regions that do not overlap.
@@ -497,24 +515,6 @@ def _regrid_area_weighted_array(
     # Assign to mask to explode it, allowing indexed assignment.
     new_data.mask = False
 
-    # Determine which grid bounds are within src extent.
-    y_within_bounds = _within_bounds(
-        src_y_bounds, grid_y_bounds, grid_y_decreasing
-    )
-    x_within_bounds = _within_bounds(
-        src_x_bounds, grid_x_bounds, grid_x_decreasing
-    )
-
-    # Cache which src_bounds are within grid bounds
-    cached_x_bounds = []
-    cached_x_indices = []
-    for (x_0, x_1) in grid_x_bounds:
-        if grid_x_decreasing:
-            x_0, x_1 = x_1, x_0
-        x_bounds, x_indices = _cropped_bounds(src_x_bounds, x_0, x_1)
-        cached_x_bounds.append(x_bounds)
-        cached_x_indices.append(x_indices)
-
     # Axes of data over which the weighted mean is calculated.
     axes = []
     if y_dim is not None:
@@ -565,15 +565,15 @@ def _regrid_area_weighted_array(
                     raise RuntimeError(
                         "Cannot handle split bounds " "in both x and y."
                     )
+                # Calculate weights based on areas of cropped bounds.
+                weights = area_func(y_bounds, x_bounds)
+
                 if x_dim is not None:
                     indices[x_dim] = x_indices
                 if y_dim is not None:
                     indices[y_dim] = y_indices
                 data = src_data[tuple(indices)]
 
-                # Calculate weights based on areas of cropped bounds.
-                weights = area_func(y_bounds, x_bounds)
-
                 # Transpose weights to match dim ordering in data.
                 weights_shape_y = weights.shape[0]
                 weights_shape_x = weights.shape[1]
diff --git a/lib/iris/fileformats/_pyke_rules/fc_rules_cf.krb b/lib/iris/fileformats/_pyke_rules/fc_rules_cf.krb
index 5ecfeb77b1..815d71a5f4 100644
--- a/lib/iris/fileformats/_pyke_rules/fc_rules_cf.krb
+++ b/lib/iris/fileformats/_pyke_rules/fc_rules_cf.krb
@@ -498,6 +498,22 @@ fc_build_cell_measure
         python engine.rule_triggered.add(rule.name)
 
 
+#
+# Context:
+#   This rule will trigger for each ancillary_variable case specific fact.
+#
+# Purpose:
+#   Add the ancillary variable to the cube.
+#
+fc_build_ancil_var
+    foreach
+        facts_cf.ancillary_variable($var)
+    assert
+        python ancil_var = engine.cf_var.cf_group.ancillary_variables[$var]
+        python build_ancil_var(engine, ancil_var)
+        python engine.rule_triggered.add(rule.name)
+
+
 #
 # Context:
 #   This rule will trigger iff a CF latitude coordinate exists and
@@ -1941,25 +1957,26 @@ fc_extras
         # Add it to the cube
         cube.add_aux_coord(coord, data_dims)
 
-        # Update the coordinate to CF-netCDF variable mapping.
+        # Make a list with names, stored on the engine, so we can find them all later.
         engine.provides['coordinates'].append((coord, cf_coord_var.cf_name))
 
 
     ################################################################################
-    def build_cell_measures(engine, cf_cm_attr, coord_name=None):
+    def build_cell_measures(engine, cf_cm_var):
         """Create a CellMeasure instance and add it to the cube."""
         cf_var = engine.cf_var
         cube = engine.cube
         attributes = {}
 
         # Get units
-        attr_units = get_attr_units(cf_cm_attr, attributes)
+        attr_units = get_attr_units(cf_cm_var, attributes)
 
-        data = _get_cf_var_data(cf_cm_attr, engine.filename)
+        # Get (lazy) content array
+        data = _get_cf_var_data(cf_cm_var, engine.filename)
 
         # Determine the name of the dimension/s shared between the CF-netCDF data variable
         # and the coordinate being built.
-        common_dims = [dim for dim in cf_cm_attr.dimensions
+        common_dims = [dim for dim in cf_cm_var.dimensions
                        if dim in cf_var.dimensions]
         data_dims = None
         if common_dims:
@@ -1967,10 +1984,10 @@ fc_extras
             data_dims = [cf_var.dimensions.index(dim) for dim in common_dims]
 
         # Determine the standard_name, long_name and var_name
-        standard_name, long_name, var_name = get_names(cf_cm_attr, coord_name, attributes)
+        standard_name, long_name, var_name = get_names(cf_cm_var, None, attributes)
 
         # Obtain the cf_measure.
-        measure = cf_cm_attr.cf_measure
+        measure = cf_cm_var.cf_measure
 
         # Create the CellMeasure
         cell_measure = iris.coords.CellMeasure(data,
@@ -1984,6 +2001,51 @@ fc_extras
         # Add it to the cube
         cube.add_cell_measure(cell_measure, data_dims)
 
+        # Make a list with names, stored on the engine, so we can find them all later.
+        engine.provides['cell_measures'].append((cell_measure, cf_cm_var.cf_name))
+
+
+
+    ################################################################################
+    def build_ancil_var(engine, cf_av_var):
+        """Create an AncillaryVariable instance and add it to the cube."""
+        cf_var = engine.cf_var
+        cube = engine.cube
+        attributes = {}
+
+        # Get units
+        attr_units = get_attr_units(cf_av_var, attributes)
+
+        # Get (lazy) content array
+        data = _get_cf_var_data(cf_av_var, engine.filename)
+
+        # Determine the name of the dimension/s shared between the CF-netCDF data variable
+        # and the AV being built.
+        common_dims = [dim for dim in cf_av_var.dimensions
+                       if dim in cf_var.dimensions]
+        data_dims = None
+        if common_dims:
+            # Calculate the offset of each common dimension.
+            data_dims = [cf_var.dimensions.index(dim) for dim in common_dims]
+
+        # Determine the standard_name, long_name and var_name
+        standard_name, long_name, var_name = get_names(cf_av_var, None, attributes)
+
+        # Create the AncillaryVariable
+        av = iris.coords.AncillaryVariable(
+            data,
+            standard_name=standard_name,
+            long_name=long_name,
+            var_name=var_name,
+            units=attr_units,
+            attributes=attributes)
+
+        # Add it to the cube
+        cube.add_ancillary_variable(av, data_dims)
+
+        # Make a list with names, stored on the engine, so we can find them all later.
+        engine.provides['ancillary_variables'].append((av, cf_av_var.cf_name))
+
 
 
     ################################################################################
diff --git a/lib/iris/fileformats/netcdf.py b/lib/iris/fileformats/netcdf.py
index 4d7ddedc61..08b079c3ed 100644
--- a/lib/iris/fileformats/netcdf.py
+++ b/lib/iris/fileformats/netcdf.py
@@ -459,7 +459,10 @@ def __setstate__(self, state):
 
 def _assert_case_specific_facts(engine, cf, cf_group):
     # Initialise pyke engine "provides" hooks.
+    # These are used to patch non-processed element attributes after rules activation.
     engine.provides["coordinates"] = []
+    engine.provides["cell_measures"] = []
+    engine.provides["ancillary_variables"] = []
 
     # Assert facts for CF coordinates.
     for cf_name in cf_group.coordinates.keys():
@@ -479,6 +482,12 @@ def _assert_case_specific_facts(engine, cf, cf_group):
             _PYKE_FACT_BASE, "cell_measure", (cf_name,)
         )
 
+    # Assert facts for CF ancillary variables.
+    for cf_name in cf_group.ancillary_variables.keys():
+        engine.add_case_specific_fact(
+            _PYKE_FACT_BASE, "ancillary_variable", (cf_name,)
+        )
+
     # Assert facts for CF grid_mappings.
     for cf_name in cf_group.grid_mappings.keys():
         engine.add_case_specific_fact(
@@ -597,31 +606,38 @@ def _load_cube(engine, cf, cf_var, filename):
     # Run pyke inference engine with forward chaining rules.
     engine.activate(_PYKE_RULE_BASE)
 
-    # Populate coordinate attributes with the untouched attributes from the
-    # associated CF-netCDF variable.
-    coordinates = engine.provides.get("coordinates", [])
-
+    # Having run the rules, now populate the attributes of all the cf elements with the
+    # "unused" attributes from the associated CF-netCDF variable.
+    # That is, all those that aren't CF reserved terms.
     def attribute_predicate(item):
         return item[0] not in _CF_ATTRS
 
-    for coord, cf_var_name in coordinates:
-        tmpvar = filter(
-            attribute_predicate, cf.cf_group[cf_var_name].cf_attrs_unused()
-        )
+    def add_unused_attributes(iris_object, cf_var):
+        tmpvar = filter(attribute_predicate, cf_var.cf_attrs_unused())
         for attr_name, attr_value in tmpvar:
-            _set_attributes(coord.attributes, attr_name, attr_value)
+            _set_attributes(iris_object.attributes, attr_name, attr_value)
+
+    def fix_attributes_all_elements(role_name):
+        elements_and_names = engine.provides.get(role_name, [])
+
+        for iris_object, cf_var_name in elements_and_names:
+            add_unused_attributes(iris_object, cf.cf_group[cf_var_name])
+
+    # Populate the attributes of all coordinates, cell-measures and ancillary-vars.
+    fix_attributes_all_elements("coordinates")
+    fix_attributes_all_elements("ancillary_variables")
+    fix_attributes_all_elements("cell_measures")
 
-    tmpvar = filter(attribute_predicate, cf_var.cf_attrs_unused())
-    # Attach untouched attributes of the associated CF-netCDF data variable to
-    # the cube.
-    for attr_name, attr_value in tmpvar:
-        _set_attributes(cube.attributes, attr_name, attr_value)
+    # Also populate attributes of the top-level cube itself.
+    add_unused_attributes(cube, cf_var)
 
+    # Work out reference names for all the coords.
     names = {
         coord.var_name: coord.standard_name or coord.var_name or "unknown"
         for coord in cube.coords()
     }
 
+    # Add all the cube cell methods.
     cube.cell_methods = [
         iris.coords.CellMethod(
             method=method.method,
diff --git a/lib/iris/tests/__init__.py b/lib/iris/tests/__init__.py
index f260bd0d26..d689738008 100644
--- a/lib/iris/tests/__init__.py
+++ b/lib/iris/tests/__init__.py
@@ -1297,12 +1297,6 @@ class MyPlotTests(test.GraphicsTest):
 )
 
 
-# TODO: remove these skips when iris-grib is fixed
-skip_grib_fail = unittest.skipIf(
-    True, "Test(s) are failing due to known problems " 'with "iris-grib".'
-)
-
-
 skip_sample_data = unittest.skipIf(
     not SAMPLE_DATA_AVAILABLE,
     ('Test(s) require "iris-sample-data", ' "which is not available."),
diff --git a/lib/iris/tests/integration/test_grib2.py b/lib/iris/tests/integration/test_grib2.py
index 1c94d424b0..691c4469d3 100644
--- a/lib/iris/tests/integration/test_grib2.py
+++ b/lib/iris/tests/integration/test_grib2.py
@@ -24,6 +24,7 @@
 if tests.GRIB_AVAILABLE:
     from iris_grib import load_pairs_from_fields
     from iris_grib.message import GribMessage
+    from iris_grib.grib_phenom_translation import GRIBCode
 
 
 @tests.skip_data
@@ -36,7 +37,6 @@ def test_gdt1(self):
         cube = load_cube(path)
         self.assertCMLApproxData(cube)
 
-    @tests.skip_grib_fail
     def test_gdt90_with_bitmap(self):
         path = tests.get_data_path(("GRIB", "umukv", "ukv_chan9.grib2"))
         cube = load_cube(path)
@@ -156,6 +156,7 @@ def test_save_load(self):
         cube.add_aux_coord(tcoord)
         cube.add_aux_coord(fpcoord)
         cube.attributes["WMO_constituent_type"] = 0
+        cube.attributes["GRIB_PARAM"] = GRIBCode("GRIB2:d000c014n000")
 
         with self.temp_filename("test_grib_pdt40.grib2") as temp_file_path:
             save(cube, temp_file_path)
@@ -232,9 +233,12 @@ def test_save_load(self):
             self.assertEqual(test_cube.shape, (744, 744))
             self.assertEqual(test_cube.cell_methods, ())
 
-        # Check no cube attributes on the re-loaded cube.
+        # Check only the GRIB_PARAM attribute exists on the re-loaded cube.
         # Note: this does *not* match the original, but is as expected.
-        self.assertEqual(cube_loaded_from_saved.attributes, {})
+        self.assertEqual(
+            cube_loaded_from_saved.attributes,
+            {"GRIB_PARAM": GRIBCode("GRIB2:d000c003n001")},
+        )
 
         # Now remaining to check: coordinates + data...
 
@@ -300,7 +304,6 @@ def test_regular(self):
         cube = load_cube(path)
         self.assertCMLApproxData(cube)
 
-    @tests.skip_grib_fail
     def test_reduced(self):
         path = tests.get_data_path(("GRIB", "reduced", "reduced_gg.grib2"))
         cube = load_cube(path)
diff --git a/lib/iris/tests/integration/test_grib_load.py b/lib/iris/tests/integration/test_grib_load.py
index 230c792756..0e7548ee34 100644
--- a/lib/iris/tests/integration/test_grib_load.py
+++ b/lib/iris/tests/integration/test_grib_load.py
@@ -136,7 +136,6 @@ def test_reduced_ll(self):
         )
         self.assertCML(cube, ("grib_load", "reduced_ll_grib1.cml"))
 
-    @tests.skip_grib_fail
     def test_reduced_gg(self):
         cube = iris.load_cube(
             tests.get_data_path(("GRIB", "reduced", "reduced_gg.grib2"))
diff --git a/lib/iris/tests/results/grib_load/3_layer.cml b/lib/iris/tests/results/grib_load/3_layer.cml
index 24f24ed777..76cc41a04a 100644
--- a/lib/iris/tests/results/grib_load/3_layer.cml
+++ b/lib/iris/tests/results/grib_load/3_layer.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
@@ -31,6 +34,9 @@
     <data checksum="0xd04cbc45" dtype="float64" shape="(360, 600)"/>
   </cube>
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
@@ -82,6 +88,9 @@
     <data checksum="0x857e5378" dtype="float64" shape="(73, 96)"/>
   </cube>
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 0.0]]" id="1d45e087" points="[0.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_0.cml b/lib/iris/tests/results/grib_load/earth_shape_0.cml
index 1e1e491d58..bb51db3201 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_0.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_0.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_1.cml b/lib/iris/tests/results/grib_load/earth_shape_1.cml
index dd409ebb20..774e9921b5 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_1.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_1.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_2.cml b/lib/iris/tests/results/grib_load/earth_shape_2.cml
index 0e3a4a14ea..3ff9ccccb5 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_2.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_2.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_3.cml b/lib/iris/tests/results/grib_load/earth_shape_3.cml
index 0213c4a4a0..47d11467ee 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_3.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_3.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_4.cml b/lib/iris/tests/results/grib_load/earth_shape_4.cml
index 2573e867d1..e6aa14e45a 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_4.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_4.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_5.cml b/lib/iris/tests/results/grib_load/earth_shape_5.cml
index 56462c684b..1257c9c2ad 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_5.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_5.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_6.cml b/lib/iris/tests/results/grib_load/earth_shape_6.cml
index 1ad54d1f77..eb96657104 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_6.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_6.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/earth_shape_7.cml b/lib/iris/tests/results/grib_load/earth_shape_7.cml
index cea76b2739..d27ce04a4c 100644
--- a/lib/iris/tests/results/grib_load/earth_shape_7.cml
+++ b/lib/iris/tests/results/grib_load/earth_shape_7.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/ineg_jneg.cml b/lib/iris/tests/results/grib_load/ineg_jneg.cml
index 344fbbacf2..a7d7741092 100644
--- a/lib/iris/tests/results/grib_load/ineg_jneg.cml
+++ b/lib/iris/tests/results/grib_load/ineg_jneg.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/ineg_jpos.cml b/lib/iris/tests/results/grib_load/ineg_jpos.cml
index 14967e6a88..f578fceadb 100644
--- a/lib/iris/tests/results/grib_load/ineg_jpos.cml
+++ b/lib/iris/tests/results/grib_load/ineg_jpos.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/ipos_jneg.cml b/lib/iris/tests/results/grib_load/ipos_jneg.cml
index 1e1e491d58..bb51db3201 100644
--- a/lib/iris/tests/results/grib_load/ipos_jneg.cml
+++ b/lib/iris/tests/results/grib_load/ipos_jneg.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/ipos_jpos.cml b/lib/iris/tests/results/grib_load/ipos_jpos.cml
index 373d8fc475..4dc6d7f980 100644
--- a/lib/iris/tests/results/grib_load/ipos_jpos.cml
+++ b/lib/iris/tests/results/grib_load/ipos_jpos.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/grib_load/lambert_grib2.cml b/lib/iris/tests/results/grib_load/lambert_grib2.cml
index e8b3f1c4c6..dc938f0aca 100644
--- a/lib/iris/tests/results/grib_load/lambert_grib2.cml
+++ b/lib/iris/tests/results/grib_load/lambert_grib2.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[2]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/grib_load/missing_values_grib2.cml b/lib/iris/tests/results/grib_load/missing_values_grib2.cml
index b090d56a92..c4c0d81915 100644
--- a/lib/iris/tests/results/grib_load/missing_values_grib2.cml
+++ b/lib/iris/tests/results/grib_load/missing_values_grib2.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="x_wind" units="m s-1">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c002n002"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/grib_load/reduced_gg_grib2.cml b/lib/iris/tests/results/grib_load/reduced_gg_grib2.cml
index f34938ce3f..fa3ba45e3d 100644
--- a/lib/iris/tests/results/grib_load/reduced_gg_grib2.cml
+++ b/lib/iris/tests/results/grib_load/reduced_gg_grib2.cml
@@ -2,6 +2,7 @@
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="geopotential" units="m2 s-2">
     <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c003n004"/>
       <attribute name="centre" value="European Centre for Medium Range Weather Forecasts"/>
     </attributes>
     <coords>
diff --git a/lib/iris/tests/results/grib_load/regular_gg_grib2.cml b/lib/iris/tests/results/grib_load/regular_gg_grib2.cml
index 20230aee0f..14213c1602 100644
--- a/lib/iris/tests/results/grib_load/regular_gg_grib2.cml
+++ b/lib/iris/tests/results/grib_load/regular_gg_grib2.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="geopotential_height" units="m">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c003n005"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[69]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/grib_load/time_bound_grib2.cml b/lib/iris/tests/results/grib_load/time_bound_grib2.cml
index 1e1e491d58..bb51db3201 100644
--- a/lib/iris/tests/results/grib_load/time_bound_grib2.cml
+++ b/lib/iris/tests/results/grib_load/time_bound_grib2.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[-28587.0, 6477.0]]" id="1d45e087" points="[-11055.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/grib2/TestDRT3/grid_complex_spatial_differencing.cml b/lib/iris/tests/results/integration/grib2/TestDRT3/grid_complex_spatial_differencing.cml
index b15c6a4308..2cfe06f8f6 100644
--- a/lib/iris/tests/results/integration/grib2/TestDRT3/grid_complex_spatial_differencing.cml
+++ b/lib/iris/tests/results/integration/grib2/TestDRT3/grid_complex_spatial_differencing.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="x_wind" units="m s-1">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c002n002"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/integration/grib2/TestGDT30/lambert.cml b/lib/iris/tests/results/integration/grib2/TestGDT30/lambert.cml
index a33d0b04ba..215a0de88d 100644
--- a/lib/iris/tests/results/integration/grib2/TestGDT30/lambert.cml
+++ b/lib/iris/tests/results/integration/grib2/TestGDT30/lambert.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[2]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/integration/grib2/TestGDT40/reduced.cml b/lib/iris/tests/results/integration/grib2/TestGDT40/reduced.cml
index f2ca666998..3a963b3203 100644
--- a/lib/iris/tests/results/integration/grib2/TestGDT40/reduced.cml
+++ b/lib/iris/tests/results/integration/grib2/TestGDT40/reduced.cml
@@ -2,6 +2,7 @@
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="geopotential" units="m2 s-2">
     <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c003n004"/>
       <attribute name="centre" value="European Centre for Medium Range Weather Forecasts"/>
     </attributes>
     <coords>
diff --git a/lib/iris/tests/results/integration/grib2/TestGDT40/regular.cml b/lib/iris/tests/results/integration/grib2/TestGDT40/regular.cml
index fb6445b8b1..e5eea0fc7c 100644
--- a/lib/iris/tests/results/integration/grib2/TestGDT40/regular.cml
+++ b/lib/iris/tests/results/integration/grib2/TestGDT40/regular.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="geopotential_height" units="m">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c003n005"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[69]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/integration/grib2/TestImport/gdt1.cml b/lib/iris/tests/results/integration/grib2/TestImport/gdt1.cml
index d3cc6b4732..d304d8a843 100644
--- a/lib/iris/tests/results/integration/grib2/TestImport/gdt1.cml
+++ b/lib/iris/tests/results/integration/grib2/TestImport/gdt1.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/integration/grib2/TestImport/gdt90_with_bitmap.cml b/lib/iris/tests/results/integration/grib2/TestImport/gdt90_with_bitmap.cml
index 9f950b5e1f..3118f86823 100644
--- a/lib/iris/tests/results/integration/grib2/TestImport/gdt90_with_bitmap.cml
+++ b/lib/iris/tests/results/integration/grib2/TestImport/gdt90_with_bitmap.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d003c000n002"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="87abc70d" long_name="instrument_type" points="[207]" shape="(1,)" units="Unit('1')" value_type="int64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEII/0_TRACER_AIR_CONCENTRATION.cml b/lib/iris/tests/results/integration/name_grib/NAMEII/0_TRACER_AIR_CONCENTRATION.cml
index 4d0fddbba5..b0daf50907 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEII/0_TRACER_AIR_CONCENTRATION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEII/0_TRACER_AIR_CONCENTRATION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 3.0]]" id="1d45e087" points="[3.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEII/1_TRACER_DOSAGE.cml b/lib/iris/tests/results/integration/name_grib/NAMEII/1_TRACER_DOSAGE.cml
index fd61a67eb6..aef4988ce6 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEII/1_TRACER_DOSAGE.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEII/1_TRACER_DOSAGE.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 3.0]]" id="1d45e087" points="[3.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEII/2_TRACER_WET_DEPOSITION.cml b/lib/iris/tests/results/integration/name_grib/NAMEII/2_TRACER_WET_DEPOSITION.cml
deleted file mode 100644
index 029aa022ea..0000000000
--- a/lib/iris/tests/results/integration/name_grib/NAMEII/2_TRACER_WET_DEPOSITION.cml
+++ /dev/null
@@ -1,31 +0,0 @@
-<?xml version="1.0" ?>
-<cubes xmlns="urn:x-iris:cubeml-0.2">
-  <cube units="unknown">
-    <coords>
-      <coord>
-        <dimCoord bounds="[[0.0, 3.0]]" id="1d45e087" points="[3.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
-      </coord>
-      <coord datadims="[0]">
-        <dimCoord id="77a50eb5" points="[52.367102, 52.368207, 52.369312, ..., 52.584787,
-		52.585892, 52.586997]" shape="(200,)" standard_name="latitude" units="Unit('degrees')" value_type="float64">
-          <geogCS earth_radius="6371229.0"/>
-        </dimCoord>
-      </coord>
-      <coord datadims="[1]">
-        <dimCoord id="f913a8b3" points="[357.9144, 357.916209, 357.918018, ...,
-		358.270773, 358.272582, 358.274391]" shape="(200,)" standard_name="longitude" units="Unit('degrees')" value_type="float64">
-          <geogCS earth_radius="6371229.0"/>
-        </dimCoord>
-      </coord>
-      <coord>
-        <dimCoord bounds="[[351249.0, 351252.0]]" id="cb784457" points="[351252.0]" shape="(1,)" standard_name="time" units="Unit('hours since 1970-01-01 00:00:00', calendar='gregorian')" value_type="float64"/>
-      </coord>
-    </coords>
-    <cellMethods>
-      <cellMethod method="sum">
-        <coord name="time"/>
-      </cellMethod>
-    </cellMethods>
-    <data checksum="0xfe476ed6" dtype="float64" shape="(200, 200)"/>
-  </cube>
-</cubes>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEII/3_TRACER_DRY_DEPOSITION.cml b/lib/iris/tests/results/integration/name_grib/NAMEII/3_TRACER_DRY_DEPOSITION.cml
index 429d9db2ff..5787c19643 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEII/3_TRACER_DRY_DEPOSITION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEII/3_TRACER_DRY_DEPOSITION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 3.0]]" id="1d45e087" points="[3.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEII/4_TRACER_TOTAL_DEPOSITION.cml b/lib/iris/tests/results/integration/name_grib/NAMEII/4_TRACER_TOTAL_DEPOSITION.cml
index 429d9db2ff..5787c19643 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEII/4_TRACER_TOTAL_DEPOSITION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEII/4_TRACER_TOTAL_DEPOSITION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 3.0]]" id="1d45e087" points="[3.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEIII/0_TRACER_AIR_CONCENTRATION.cml b/lib/iris/tests/results/integration/name_grib/NAMEIII/0_TRACER_AIR_CONCENTRATION.cml
index 8412a4f814..1a31427de0 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEIII/0_TRACER_AIR_CONCENTRATION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEIII/0_TRACER_AIR_CONCENTRATION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 4.0]]" id="1d45e087" points="[4.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEIII/1_TRACER_AIR_CONCENTRATION.cml b/lib/iris/tests/results/integration/name_grib/NAMEIII/1_TRACER_AIR_CONCENTRATION.cml
index 590e8ef463..7007836e62 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEIII/1_TRACER_AIR_CONCENTRATION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEIII/1_TRACER_AIR_CONCENTRATION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 1.0]]" id="1d45e087" points="[1.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEIII/2_TRACER_DRY_DEPOSITION.cml b/lib/iris/tests/results/integration/name_grib/NAMEIII/2_TRACER_DRY_DEPOSITION.cml
index d3edb03a56..850ef89ed2 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEIII/2_TRACER_DRY_DEPOSITION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEIII/2_TRACER_DRY_DEPOSITION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 4.0]]" id="1d45e087" points="[4.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEIII/3_TRACER_WET_DEPOSITION.cml b/lib/iris/tests/results/integration/name_grib/NAMEIII/3_TRACER_WET_DEPOSITION.cml
index 3e8d62ef3d..ade4cea92d 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEIII/3_TRACER_WET_DEPOSITION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEIII/3_TRACER_WET_DEPOSITION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 4.0]]" id="1d45e087" points="[4.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/integration/name_grib/NAMEIII/4_TRACER_DEPOSITION.cml b/lib/iris/tests/results/integration/name_grib/NAMEIII/4_TRACER_DEPOSITION.cml
index 586aaa6b56..088b622c46 100644
--- a/lib/iris/tests/results/integration/name_grib/NAMEIII/4_TRACER_DEPOSITION.cml
+++ b/lib/iris/tests/results/integration/name_grib/NAMEIII/4_TRACER_DEPOSITION.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" units="unknown">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d255c255n255"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord bounds="[[0.0, 4.0]]" id="1d45e087" points="[4.0]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="float64"/>
diff --git a/lib/iris/tests/results/system/supported_filetype_.grib2.cml b/lib/iris/tests/results/system/supported_filetype_.grib2.cml
index c230684fbd..f334b13863 100644
--- a/lib/iris/tests/results/system/supported_filetype_.grib2.cml
+++ b/lib/iris/tests/results/system/supported_filetype_.grib2.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="wind_speed" units="m s-1">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c002n001"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="1d45e087" points="[9]" shape="(1,)" standard_name="forecast_period" units="Unit('hours')" value_type="int64"/>
diff --git a/lib/iris/tests/results/uri_callback/grib_global.cml b/lib/iris/tests/results/uri_callback/grib_global.cml
index a7a23e7235..aef0310a96 100644
--- a/lib/iris/tests/results/uri_callback/grib_global.cml
+++ b/lib/iris/tests/results/uri_callback/grib_global.cml
@@ -1,6 +1,9 @@
 <?xml version="1.0" ?>
 <cubes xmlns="urn:x-iris:cubeml-0.2">
   <cube dtype="float64" standard_name="air_temperature" units="K">
+    <attributes>
+      <attribute name="GRIB_PARAM" value="GRIB2:d000c000n000"/>
+    </attributes>
     <coords>
       <coord>
         <dimCoord id="507906da" long_name="extra_year_number_coord" points="[1998]" shape="(1,)" units="Unit('no_unit')" value_type="int64"/>
diff --git a/lib/iris/tests/test_netcdf.py b/lib/iris/tests/test_netcdf.py
index a550e1ed4b..91e37dd3a8 100644
--- a/lib/iris/tests/test_netcdf.py
+++ b/lib/iris/tests/test_netcdf.py
@@ -16,6 +16,7 @@
 import os.path
 import shutil
 import stat
+from subprocess import check_call
 import tempfile
 from unittest import mock
 
@@ -27,8 +28,10 @@
 import iris.analysis.trajectory
 import iris.fileformats._pyke_rules.compiled_krb.fc_rules_cf_fc as pyke_rules
 import iris.fileformats.netcdf
+from iris.fileformats.netcdf import load_cubes as nc_load_cubes
 import iris.std_names
 import iris.util
+from iris.coords import AncillaryVariable, CellMeasure
 import iris.coord_systems as icoord_systems
 import iris.tests.stock as stock
 from iris._lazy_data import is_lazy_data
@@ -36,6 +39,13 @@
 
 @tests.skip_data
 class TestNetCDFLoad(tests.IrisTest):
+    def setUp(self):
+        self.tmpdir = None
+
+    def tearDown(self):
+        if self.tmpdir is not None:
+            shutil.rmtree(self.tmpdir)
+
     def test_monotonic(self):
         cubes = iris.load(
             tests.get_data_path(
@@ -240,6 +250,104 @@ def test_cell_methods(self):
 
         self.assertCML(cubes, ("netcdf", "netcdf_cell_methods.cml"))
 
+    def test_ancillary_variables(self):
+        # Note: using a CDL string as a test data reference, rather than a binary file.
+        ref_cdl = """
+            netcdf cm_attr {
+            dimensions:
+                axv = 3 ;
+            variables:
+                int64 qqv(axv) ;
+                    qqv:long_name = "qq" ;
+                    qqv:units = "1" ;
+                    qqv:ancillary_variables = "my_av" ;
+                int64 axv(axv) ;
+                    axv:units = "1" ;
+                    axv:long_name = "x" ;
+                double my_av(axv) ;
+                    my_av:units = "1" ;
+                    my_av:long_name = "refs" ;
+                    my_av:custom = "extra-attribute";
+            data:
+                axv = 1, 2, 3;
+                my_av = 11., 12., 13.;
+            }
+            """
+        self.tmpdir = tempfile.mkdtemp()
+        cdl_path = os.path.join(self.tmpdir, "tst.cdl")
+        nc_path = os.path.join(self.tmpdir, "tst.nc")
+        # Write CDL string into a temporary CDL file.
+        with open(cdl_path, "w") as f_out:
+            f_out.write(ref_cdl)
+        # Use ncgen to convert this into an actual (temporary) netCDF file.
+        command = "ncgen -o {} {}".format(nc_path, cdl_path)
+        check_call(command, shell=True)
+        # Load with iris.fileformats.netcdf.load_cubes, and check expected content.
+        cubes = list(nc_load_cubes(nc_path))
+        self.assertEqual(len(cubes), 1)
+        avs = cubes[0].ancillary_variables()
+        self.assertEqual(len(avs), 1)
+        expected = AncillaryVariable(
+            np.ma.array([11.0, 12.0, 13.0]),
+            long_name="refs",
+            var_name="my_av",
+            units="1",
+            attributes={"custom": "extra-attribute"},
+        )
+        self.assertEqual(avs[0], expected)
+
+    def test_cell_measures(self):
+        # Note: using a CDL string as a test data reference, rather than a binary file.
+        ref_cdl = """
+            netcdf cm_attr {
+            dimensions:
+                axv = 3 ;
+                ayv = 2 ;
+            variables:
+                int64 qqv(ayv, axv) ;
+                    qqv:long_name = "qq" ;
+                    qqv:units = "1" ;
+                    qqv:cell_measures = "area: my_areas" ;
+                int64 ayv(ayv) ;
+                    ayv:units = "1" ;
+                    ayv:long_name = "y" ;
+                int64 axv(axv) ;
+                    axv:units = "1" ;
+                    axv:long_name = "x" ;
+                double my_areas(ayv, axv) ;
+                    my_areas:units = "m2" ;
+                    my_areas:long_name = "standardised cell areas" ;
+                    my_areas:custom = "extra-attribute";
+            data:
+                axv = 11, 12, 13;
+                ayv = 21, 22;
+                my_areas = 110., 120., 130., 221., 231., 241.;
+            }
+            """
+        self.tmpdir = tempfile.mkdtemp()
+        cdl_path = os.path.join(self.tmpdir, "tst.cdl")
+        nc_path = os.path.join(self.tmpdir, "tst.nc")
+        # Write CDL string into a temporary CDL file.
+        with open(cdl_path, "w") as f_out:
+            f_out.write(ref_cdl)
+        # Use ncgen to convert this into an actual (temporary) netCDF file.
+        command = "ncgen -o {} {}".format(nc_path, cdl_path)
+        check_call(command, shell=True)
+        # Load with iris.fileformats.netcdf.load_cubes, and check expected content.
+        cubes = list(nc_load_cubes(nc_path))
+        self.assertEqual(len(cubes), 1)
+        cms = cubes[0].cell_measures()
+        self.assertEqual(len(cms), 1)
+        expected = CellMeasure(
+            np.ma.array([[110.0, 120.0, 130.0], [221.0, 231.0, 241.0]]),
+            measure="area",
+            var_name="my_areas",
+            long_name="standardised cell areas",
+            units="m2",
+            attributes={"custom": "extra-attribute"},
+        )
+        self.assertEqual(cms[0], expected)
+
     def test_deferred_loading(self):
         # Test exercising CF-netCDF deferred loading and deferred slicing.
         # shape (31, 161, 320)