/var/db/sup/src-all/checkouts.cvs:RELENG_5 ? May I delete?

Hi,

On one of my PCs I'm using 5.X and csvup to RELENG_5.

There appear huge files in /var:

   /var/db/sup/src-all/checkouts.cvs:RELENG_5
   /var/db/sup/ports-all/checkouts.cvs:.

Do I have to keep these files? If yes, what for?

Also /var/db/pkg/  consumes lots of space in /var.
Do I have to keep that as well?

Thanks,
Rob.