A numeric argument restricts replacement to matches that are surrounded
by word boundaries. The argument's value doesn't matter.
+ @xref{Replacement and Case}, for details about case-sensitivity in
+replace commands.
+
What if you want to exchange @samp{x} and @samp{y}: replace every @samp{x} with a @samp{y} and vice versa? You can do it this way:
@example
occurrence and asks you whether to replace it. Aside from querying,
@code{query-replace} works just like @code{replace-string}. It
preserves case, like @code{replace-string}, provided
-@code{case-replace} is non-@code{nil}, as it normally is. A numeric
-argument means consider only occurrences that are bounded by
-word-delimiter characters.
+@code{case-replace} is non-@code{nil}, as it normally is
+(@pxref{Replacement and Case}). A numeric argument means consider
+only occurrences that are bounded by word-delimiter characters.
@kindex C-M-%
@findex query-replace-regexp