Over in the ZPM group I noticed someone posting using the REGREAD
command and thought it had to be external and wouldn't it be nice if it
was built-in. Looking further, seems this has been built into the login
script for many YEARS now!!

Can I suggest here that it should be added to the docs? Or would the
enhancement request be the way to go?

It has been suggested in these forums in the past that regread be added
to the doc, but it obviously remained a secret (not the closely guarded
type, more like the secure-through-obscurity or undocumented feature type).