rcs: Revision options

 
 2.1.1 Revision options
 ----------------------
 
 As to be expected in a revision control system, many options are of the
 form ‘-FLAG[REV]’, where FLAG is a single letter (e.g., ‘r’).  If
 ommitted, REV defaults to the latest revision on the default branch.  A
 revision can be specified in many ways:
 
 BR.N
      Straightforward dot-notation, where BR specifies the branch.
 
 .N
      Like BR.N, using the default branch.
 
 BR
      Like BR.N, using the a command-specific computation of N, given the
      current tip I.  For ci (⇒ci), N would be ‘I + 1’, while for
      other commands N would be simply I.
 
 NAME
      This is the symbolic name of a revision, as assigned previously by
      a ‘ci -n’ or ‘ci -N’ command.
 
 $
      The command computes the effective revision by examining the values
      of keyword expansions in the working file.
 
 For commands that accept a range of revisions, the syntax is generally
 ‘REV1:REV2’, i.e., two revisions (specified as described above)
 separated by a colon.