I notice in the Utility mnemonics section of the documentation, here on the mod portal and on the gitlab repo, that only one such mnemonic is documented (ugpf). There is a second (uiss) that is briefly mentioned as a comment on a use of ugpf, but there is no other documentation about it. Is this intentional? Are there other utility mnemonics that are not yet documented that are currently still under development and have not been finalized yet?