The multiple attack penalty you take with this weapon on the second attack on your turn is –4 instead of –5, and –8 instead of –10 on the third and subsequent attacks in the turn.

You can use your Dexterity modifier instead of your Strength modifier on attack rolls using this melee weapon. You still use your Strength modifier when calculating damage.

This weapon doesn't take up your hand, usually because it is built into your armor. A free-hand weapon can't be Disarmed. You can use the hand covered by your free-hand weapon to wield other items, perform manipulate actions, and so on. You can't attack with a free-hand weapon if you're wielding anything in that hand or otherwise using that hand. When you're not wielding anything and not otherwise using the hand, you can use abilities that require you to have a hand free as well as those that require you to be wielding a weapon in that hand. Each of your hands can have only one free-hand weapon on it.

The weapon has multiple configurations that you can switch between using an Interact action. Typically, switching between configurations of a modular weapon allows it to deal different types of damage (listed in the trait, such as “modular B, P, or S”), though it’s possible for a modular weapon’s description to list more complicated configurations.

Something of uncommon rarity requires special training or comes from a particular culture or part of the world. Some character choices give access to uncommon options, and the GM can choose to allow access for anyone. Less is known about uncommon creatures than common creatures. They typically can't be summoned. The DC of Recall Knowledge checks related to these creature is increased by 2.