@kbd{C-x v =} works by running a variant of the @code{diff} utility
designed to work with the version control system in use. When you
invoke @code{diff} this way, in addition to the options specified by
-@code{diff-switches} (@pxref{Comparing files}), it receives those
+@code{diff-switches} (@pxref{Comparing Files}), it receives those
specified by @code{vc-diff-switches}, plus those specified for the
specific back end by @code{vc-@var{backend}-diff-switches}. For
instance, when the version control back end is RCS, @code{diff} uses