Definitions by Shaco

Jamms 

A descriptive word for someone, usually a female who has rather large jugs, but can also be if needed used to describe your Texan uncle Bobby "Big Jamms" Mahooney

Can also be used to describe a rather tight top that has caused items to be squeezed or packed tightly into a specified space

Belltower - "Woah, did you see the Jamms on that waitress in the VIP section"

Atlas - "Woof!"

Jamms by Shaco August 12, 2021

OCG

Stands for

O-Official
C-Card
G-Grammar

This refers to specific phrases and terminology that should be used when creating a card for a certain trading card game.
Namely Yugioh.

Bad OCG - lose 500 lifepoints, then summon a card with less than or equal to 1500 attack points from your deck or grave to your side of the field. When your turn is done, remove the summoned monster from the game entirely.

Correct OCG - Pay 500 Life Points. Special Summon 1 monster with an ATK of 1500 or less from your Deck or Graveyard. At the End Phase, remove from play the monster that was Special Summoned by this effect.

OCG by Shaco January 11, 2009