Peg Revision Syntax

I'm adding support for peg revision syntax to 'svn copy' and I just want
to make sure that I've got things straight with regard to peg revisions
(peg revs), and operational revisions (op revs).

Each source needs both a peg rev, and an op rev, which may be different.
  Depending on which combinations of peg rev and op rev happen several
scenarios are possible. By my count, there are four possible cases for
each source:

1) No peg rev, no op rev
Example: 'svn cp src dst'
Peg rev: HEAD
Op rev: HEAD

2) No peg rev, op rev
Example: 'svn cp src dst -r 200'
Peg rev: 200
Op rev: 200

3) peg rev, no op rev
Example: 'svn cp src@300 dst'
Peg rev: 300
Op rev: 300

4) peg rev and op rev
Example: 'svn cp src@300 dst -r 200'
Peg rev: 300
Op rev: 200

Each of these can be easily extended for multiple sources.

Is this correct? Are there other cases which I need to take into account?

-Hyrum