Questions about lower & fire control groups

[FRANK]

i have a 33 kit & am wanting to know what the markings are where the safety selector is on the lower, it is marked, S U O Also what is meant by " clipped & pinned lower" . as far as fire control groups how do i know which one i have, there are no markings that i can find. once again any info will be greatly appriciated

[lugerguards]

i have a 33 kit & am wanting to know what the markings are where the safety selector is on the lower, it is marked, S U O Also what is meant by " clipped & pinned lower" . as far as fire control groups how do i know which one i have, there are no markings that i can find. once again any info will be greatly appriciated

suo is the same as sef. suo is the malyasian translation. basically safe. single. full. the exact terminology begets me. as far as clip and pin. take your full auto lower and convert it to a semi shelf lower with the look of a full. but it is semi, it also appears as a pinned lower, hope this helps.