What is a PALACE?

[Strategia_In_Ultima]

There are several such abilities IIRC; modders often use them to add a description bullet to the component/facility/hull/etc. description. This can be handy to poin out such things as special damage types for weapons, target types, etc.

[Fyron]

All weapon stats and info other than to hit modifier are shown in-game already. This is the only one that needs an ability tag or adding to the description, really.