diff --git a/README.md b/README.md
index c4dcf24..1a00093 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,13 @@ Now you can use the `yc` operator on any motion or text object, such as `yc)`
 to capitalize from the cursor to the beginning of the next sentence, or `ycap`
 to capitalize every word in the paragraph.
 
+### Buffer-local mappings
+
+When you want a mapping to apply only to the current buffer, prepend `<buffer>`
+to the left hand side of the mapping.
+
+    :MapExpress <buffer>cd '/* ' . v:val . ' */'
+
 ### NOTE
 
 At the time of loading your `.vimrc` file, the commands `:MapExpress` and
diff --git a/doc/express.txt b/doc/express.txt
index 92ec3da..8c6e56e 100644
--- a/doc/express.txt
+++ b/doc/express.txt
@@ -30,6 +30,12 @@ COMMANDS                                        *express-commands*
                         {op} as the left hand side of the mapping.
                         See |:substitute| for help on substitutions.
 
+                                                *express-<buffer>*
+When you want a mapping to apply only to the current buffer, prepend <buffer>
+to the left hand side of the mapping.
+
+    :MapExpress <buffer>cd '/* ' . v:val . ' */'
+
 MAPPINGS                                        *express-mappings*
 
                                                 *g=*