WordPress vs. WP usage. Where is the source?

I’ve got a question that is kind of strange.
There is a lot going on about how third-parties are supposed to use “WP” instead of “WordPress” in their company/site/product name to differentiate it from official WordPress things (i.e. directly by an agency of the WordPress company). By reason of example, it would be the difference between “www.ads-software.com” and “WP Super Cache”.

Anyway, I am very certain that I have read this principle on this site somewhere… but now I can’t find it! I’ve done several searches, but I can’t remember very much about where I found it, and I can’t seem to hit on search terms that will reveal the article. If anyone who knows where to find this info would post a link, I would be very grateful!

Thanks,
MB3D

P.S. Mods: If my query is in some way not in accordance with the forum rules (i.e. I must find it on my own), please delete this thread. Thanks ??