Change previous version message 

rcs -mrev:msg
rcs -m1.2:"String Attr works" DbKnn.java

check out old revision 

co -l[rev]

-l is the same as -r, except that it not only retrieves but also locks the retrieved revision for the caller.

Nok to co old revision and ci as head 

$ co -l1.1.1.1 mencvcd
RCS/mencvcd,v  -->  mencvcd
revision 1.1.1.1 (locked)
done
$ ci -l1.2 -m'- co from my v1.1.1.1. cosmetic changes' mencvcd
RCS/mencvcd,v  <--  mencvcd
ci: RCS/mencvcd,v: no lock set by tong for revision 1.1

documented on: 2005.08.04

delete revision 

Help 

-orange
     deletes ("outdates") the revisions given by  range.   A
     range consisting of a single revision number means that
     revision.  A range consisting of a branch number  means
     the  latest  revision  on  that branch.  A range of the
     form rev1:rev2 means revisions rev1 to rev2 on the same
     branch,  :rev  means  from  the beginning of the branch
     containing rev up to and including rev, and rev:  means
     from  revision  rev to the end of the branch containing
     rev.  None of the outdated revisions can have  branches
     or locks.

Working History 

$ rcs -o1.2:1.4 $vcsf
RCS file: RCS/table_db.tcl,v
deleting revision 1.4
deleting revision 1.3
deleting revision 1.2