[format.string.std] Provide a definition for the locale-specific form.

Author: Dawn Perchik

source/utilities.tex

@@ -19887,10 +19887,9 @@
 For string types it specifies how many characters will be used from the string.
 
 \pnum
-The \tcode{L} option causes
-the \defnx{locale-specific form}{locale-specific form!format string}
-to be used for the conversion.
-This option is only valid for arithmetic types, and
+When the \tcode{L} option is used, the form used for the conversion is called
+the \defnx{locale-specific form}{locale-specific form!format string}.
+The \tcode{L} option is only valid for arithmetic types, and
 its effect depends upon the type.
 \begin{itemize}
 \item