Specifies the suffixes for RCS files. A nonempty suffix matches any pathname ending in the suffix. An empty suffix matches any pathname of the form RCS/path or path1/RCS/path2. The -x option can specify a list of suffixes separated by /. For example, -x,v/ specifies two suffixes: ,v and the empty suffix. If two or more suffixes are specified, they are tried in order when looking for an RCS file; the first one that works is used for that file. If no RCS file is found but an RCS file can be created, the suffixes are tried in order to determine the new RCS file's name. The default for suffixes is installation-dependent; normally it is ,v/ for hosts like Unix that permit commas in filenames, and is empty (i.e. just the empty suffix) for other hosts.