Proficiency

Some specific actions or tests will require Proficiency, this means that just having that skill is not enough to attempt those tests and you need some specialized training to do so properly.
A character who is not proficient at something has a major disadvantage when attempting it. In the case of Armor Proficiency, if a character is not proficient at using the armor they are wearing they instead gained increased Encumbrance.

Weapon Proficiency	Actions
Advanced Weapons	Attacking with an Advanced Weapon
Exotic Weapons	Attacking with an Exotic Weapon
Firearms	Attacking with a Firearm
Martial Weapons	Attacking with a Martial Weapon
Unarmed Fighting	Attacking someone using only your body or weapons with the Unarmed quality.

Armor Proficiency	Actions
Medium Armor	Wearing Medium Armor.
Heavy Armor	Wearing Heavy or Medium Armor
Powered Armor	Wearing Powered Armor

Combat Proficiency	Actions
Unarmed Maneuvers	Using Unarmed Special Combat Maneuvers
Armed Maneuvers	Using Armed Special Combat Maneuvers
Ranged Maneuvers	Using Ranged Special Combat Maneuvers
Shield Maneuvers	Using Shield Special Combat Maneuvers.

Piloting Proficiency	Actions
Spaceship Piloting	Piloting Vehicles in Space/0G
Interstellar Navigation	Directing a Vehicle thought a Hyperspace Jump
Combat Piloting	Piloting a Warmech or War Vehicle

Technical Proficiency	Actions
Hacking	Hacking and Electronic Decryption Using Programming Kits and Decoders. Using Combat ECM.
Healing	Restoring Hit Points. Treating Physical Conditions, Injuries and Wounds. Using Medkits. Performing Surgery.
Chemistry	Identifying substances and their properties. Creating substances, drugs and explosives. Using Chemistry Kits.
Engineering	Repairing complex machines (Mechs, Spaceships, Drones, Firearms, Advanced Weapons, Implants, etc) Building complex machines. Using Engineering Kits and Toolboxes.
Smithing	Repairing Armor, Simple, Martial and Exotic weapons. Crafting Armor, Simple, Martial and Exotic weapons. Using Smithing Tools and Toolboxes.
Tinkering	Repairing small objects, items and accessories. Crafting small objects, items, accessories and ammunition. Using Trapmaking Kits and Toolboxes.

Social Proficiency	Action
Animal Handling	Commanding an animal. Riding a mount. Training an animal.
Larceny	Picking locks and pockets. Making forgeries and falsifying documents. Using Larceny Special Combat Maneuvers Using Lockpicks and Forgery Kits.
Art	Creating works of art and other means of artistic expression. Creating High Quality and Masterwork gear. Using Make-up Kits and Costuming Kits.