Short Forms & Abbreviations?

And to answer your question ahead of time, I have searched thoroughly but only to no avail.

What do certain short forms likw THK, PIP(s), PuG, etc stand for?

Is there a thread for this?

Pug - Pick up group (random group bands together for x objective) - not in link
THK - no clue? - not in link

Link is very good source for others

Both were in link, just have to click the 'Abbrevations' subcategory from that