Package in STASH

I am adding some new diagnostics to a UM run (u-cn956) and would like to include them in a new package. I want to do this, so I can have one stream go out as netcdf, can easily add/subtract diagnostics and turn it off. I can see ways of turning on and off existing packages, but can’t see any way of adding a new package. So how do I do that?

The answer seems to be just create a diagnostic with that package name and it gets created.