What are the characters at the end of words in Frame dictionary?

I am trying to modify the Frame dictionary, and I am wondering what are the characters that are at the ends of some of the words?

For example:

airlift/MDSG

airliner/M

airline/SRMZ

airlock/MS

airmail/DSG

airman/M

airmass

air/MDRTZGJS

What do all of those mean? Is there some document that explains them all as there are a lot more than these.

Thanks