ALL of the 118's are police department talkgroups used either by individual departments of special operations groups. They are 100% enc all the time. The only way we will tag those is to get our hands on a PD radio and do some testing... so those are going to stay blank..
All of the 310's are EMS enc talkgroups, 100% enc all the time. They are most likey EMS to hospital talkgroups to call in when en route, and are not going to be IDable.
I believe, and do not quote me, that 21817 is the ENC fire command tg, but I will have to check my notes to verify.
As for 51031 and 51056, I am not sure which township they blong to, but they are municipal talkgroups. I will do some research on those.