-static char *diff_cache_usage =
-"git-diff-cache [-p] [-r] [-z] [-m] [-M] [-C] [-R] [-S<string>] [-O<orderfile>] [--cached] <tree-ish> [<path>...]";
+static const char diff_cache_usage[] =
+"git-diff-cache [-m] [--cached] "
+"[<common diff options>] <tree-ish> [<path>...]"
+COMMON_DIFF_OPTIONS_HELP;