$Name[tab]$Sub-Name where Name is the name of the Ability (e.g. Uncanny Dodge) and Sub-Name is the modifier name of the ability (e.g. Dex bonus to AC). When you add or subtract a level with (SPECIALS) tag on the SpecialAbility, PCGen will adjust the ability according to the order the ability is found in the SPECIALS.LST file.
The first time you gain an ability, you get the first reference to it in the SPECIALS.LST file, the second time you get the second listing, and so on.
Within the SPECIALS.LST file, additions to the different special abilities can be mixed, but the ordering within the file for each special ability is important.