What does the "R" and "G" in the R&G Department level stand for?

Presumably, this is supposed to be the R&D Department, or Research and Development Department, but given that this is the Gungeon, I can't help but feel it must be some gun related pun.

I can't find any information on the wiki or anywhere in the Ammonomicon entries, so presumably it's just an ambiguous R&G Dept. But if there is a meaning, what do they stand for?

Solution 1:

According to the official wiki, it's a play on

• "RNG" (Random Number Generator, the thing people blame when randomness works against them)
• "R&D Department" (Research & Development, a common department in many companies)

However, they give no source. They also mention

It is unconfirmed what the acronym actually stands for.