Only for the most part those aren't complete.
44 is a gang.
5 is a disturbance (as on the list).
You'll often hear "a 44 5" as a call.
On some calls "A" that means it's in progress. "B" means it's a past incident.
Signal 20 is usually used during pursuits to close Channel 1. That's if they still do pursuits.
"800" is the Brockton Towing Association. The police call, or at least used to, them on Channel 2 to request a tow.
The list I have is from 2010 and I don't know how accurate it is now. The ones I listed I heard up there until we moved out of state.
If you give me some others it might jog my memory.