I was looking at the Blogs and noticed the lack of a blog on pup language. 
Soooo... I wanted to start the ball rolling:

Ball?! WHERE!?

Hood:/Muzzle: Gear worn on the head that pups the human into the pup mindspace. Usually made out of neoprene or leather. 

Collar: Usually signifies that a pup is taken or has a handler/trainer

Mitts/Knee Pads/Paws: Padded and worn on the hands and knees to help with being on all fours.

Pack: A group of pups and handlers

Scratches/Pets: Who doesn’t like being pet and have their back scratched? *wags tail* Always ask a pup/handler before you pet them. 

Treat: “Who’s been a good boy?” Often little snacks given as a treat to pups for doing something good. 

Tail: Come as insertable or on-belt.*wags wags*

Toys: Any other toy used to play with a pup (sexual or non-sexual)

Flag/Hanky: A flag or hanky with pups, bones or paws helps get the message across that you're into pup play (specially when not wearing a hood/muzzle). Also, certain colors may mean different things.  

Mosh: When a whole group of puppies get together and play. 

ROLES: 

Pups/Puppy: Someone who identifies with that headspace. They are more about the canine head space than the physical, though physical aspects may and do come into it as well.

Dog: Someone who identifies more with the obedient side and less playful side. 

Dogboy/Puppyboy: Someone who identifies as both a puppy and as a boy. A boy is someone who is a bit more submissive. 

Alphas: Are the more dominating pups. They will pose themselves as pack leaders, but will often also look after the pups in their pack.

Beta: Any pup who is submissive to their Alpha

Omega: The most submissive role in a pack structure

Stray/Uncollared: A pup who is not wearing a collar, 

Slavepup: Someone who is into very intense play, and they are pretty much owned by their handler. 

Devildog: Someone who was or is in the military. 

Pigpup: Is into grungeplay. 

Service dog: Someone who is looking to make others very happy with their service. 

Handlers: Anyone the takes care of a pup. The one holding the leash or controls the pup. 

Trainers: Someone who takes in puppies and trains them.

Master/Mistress: Someone generally very dominant. 

Daddy/Mommy: It’s more of a family and loving relationship.

I will admit I am not perfect, and some definitions might not be on-point, but if you want to add something to the list or think something is not right, comment about it bellow :)