Adding ringcodes to the DB is kind of problematic. People don't know what to include and what to ignore (barcodes, logos, those little o oo oooooooo things Sony discs have), sometimes they miss stuff because it's small and they don't know what to look for, sometimes they mistranscribe stuff or order things in different ways, etc. For consoles the mods can tell people if something is missing or wrong, but for things like PC or audio CDs there's a lot more variation.
So, I've begun making wiki pages for different disc manufacturers and the kinds of ringcodes they use. See the page for Future Media for an idea of what I'm planning. But I can only describe the discs I've seen up close myself, so I need someone else to describe the other types. And also I need people to check that when I've listed one of their discs as a particular type, that it actually matches the description (since I haven't seen the discs, I'm just going by what's in the DB).
I've also started a big List of SID codes. Mostly for curiosity but it can also help to make sure the codes are correct or to help identify regions.