CVS - single letter codes

Update and Checkout will list a status code for each file:

U filename
The file was brought up to date with respect to the repository. This is done for any file that exists in the repository but not in your source, and for files that you haven't changed but are not the most recent versions available in the repository.
P filename
Like `U', but the CVS server sends a patch instead of an entire file. These two operations accomplish the same thing.
A filename
The file has been added to your private copy of the sources, and will be added to the source repository when you run commit on the file. A reminder to you that the file needs to be committed.
R filename
The file has been removed from your private copy of the sources, and will be removed from the source repository when you run commit on the file. This is a reminder to you that the file needs to be committed.
M filename
The file is modified in your working directory. `M' can indicate one of two states for a file you're working on: either there were no modifications to the same file in the repository, so that your file remains as you last saw it; or there were modifications in the repository as well as in your copy, but they were merged successfully, without conflict, in your working directory. CVS will print some messages if it merges your work, and a backup copy of your working file (as it looked before you ran update) will be made. The exact name of that file is printed while update runs.
C filename
A conflict was detected while trying to merge your changes to file with changes from the source repository. file (the copy in your working directory) is now the result of attempting to merge the two revisions; an unmodified copy of your file is also in your working directory, with the name `.#file.revision' where revision is the revision that your modified file started from. (Note that some systems automatically purge files that begin with `.#' if they have not been accessed for a few days. If you intend to keep a copy of your original file, it is a very good idea to rename it.) Under VMS, the file name starts with `__' rather than `.#'.
? filename
filename is in your working directory, but does not correspond to anything in the source repository, and is not in the list of files for CVS to ignore