All RCS commands accept --help and --version. See Command-Line Interfaces in The GNU Coding Standards.
Aside from --help and --version, RCS commands take the form ‘-letter[arg]’, i.e., a hyphen followed by a single letter, optionally followed by extra information. The square braces mean that the extra information is optional. (No square braces means that the extra information is required.) In any case, when specified, the extra information must abut the letter; there can be no intervening whitespace.
co -u 1.4 foo # wrong, space between -u and 1.4 co -u1.4 foo # ok
Furthermore, options must appear before file names (if any) on the command line.
ident foo -q # wrong, option after file name ident -q foo # ok
Lastly, pairs of RCS and working files can be specified in three ways: (a) both are given, (b) only the working file is given, (c) only the RCS file is given. For (a), both RCS and working files may have arbitrary directory components; RCS commands pair them up intelligently. For (b), RCS commands will look first into the directory ./RCS, if it exists, to find the associated RCS file.