I just use my trade forum and keep it in drafts titled with what the coding is for. that's my best suggestion for you, since there are no coding storage forums that I am aware of.
โ๐ต๐ฉ๐ช๐ฏ๐จ๐ด ๐ค๐ฉ๐ข๐ฏ๐จ๐ฆ, xxx๐ด๐ถ๐ฎ๐ฎ๐ฆ๐ณ ๐ฆ๐ฏ๐ฅ๐ดโ xxx โข call me axel (she/they) โข adopt a newbie โข toyhouse โข listography
You are not allowed to store signature/thread/trade rule/etc. coding on the forums. You can save it in a draft as said above, or PM is to yourself, or store it off-site. You can store RP characters here, and non-RP characters here