Do you remember that I'd created a folder in the gretl repository (called PO)? After this I sent a request to SourceForge and they said that this task could be done by myself (in the past, only the SourceForge was able to delete modules in the repositories).
The topic "CVS self-service repository management launched 2008-12-11" explains how to do this, but, unfortunately, I was unable to do this (I really need to improve my CVS skills). The topic says:
SourceForge.net now permits project administrators to perform file management operations on their CVS repositories via our interactive shell service. This capability can be used for changing file permissions, renaming/moving/deleting files, directories and modules within the repository, and also permits file editing. In the past it has always been necessary to have SourceForge.net staff perform these operations on your behalf.
To use this facility, login to an interactive shell and follow the instructions you see when you run: