R [path]

Like "A", an "R" lets you know that this file is scheduled for removal. The file will be removed from the repository as soon as you "cvs commit".

M [path]

This means that this file has been modified by you; additionally, it's possible that new changes from the repository were merged into this file successfully.

C [path]

The "C" character indicates that this file has a conflict and requires manual fixing before you can "cvs commit" your changes.