If you mean so that I wouldn't have to qualify the constants (LOCK_FILENAME instead of MyDefs::LOCK_FILENAME), I prefer specifying the package name in the references. I think that it reduces the likelihood of name collisions.
Donate to UBBDev today to help aid in Operational, Server and Script Maintenance, and Development costs.
Please also see our parent organization VNC Web Services if you're in the need of a new UBB.threads Install or Upgrade, Site/Server Migrations, or Security and Coding Services.