-This function returns the documentation string that is recorded in
-@var{symbol}'s property list under property @var{property}. It
-retrieves the text from a file if the value calls for that. If the
-property value isn't @code{nil}, isn't a string, and doesn't refer to
-text in a file, then it is evaluated to obtain a string.
+This function returns the documentation string recorded in
+@var{symbol}'s property list under property @var{property}. It is
+most often used to look up the documentation strings of variables, for
+which @var{property} is @code{variable-documentation}. However, it
+can also be used to look up other kinds of documentation, such as for
+customization groups (but for function documentation, use the
+@code{documentation} command, below).
+
+If the value recorded in the property list refers to a documentation
+string stored in a @file{DOC-@var{version}} file or a byte-compiled
+file, it looks up that string and returns it. If the property value
+isn't @code{nil}, isn't a string, and doesn't refer to text in a file,
+then it is evaluated as a Lisp expression to obtain a string.