Bootstrapping a Skill Focus requiring custom text
 

A quick one: how can I bootstrap a Skill Focus for a skill requiring custom input, for example Knowledge (other)?

For example, if I have a race that has access to the skills Knowledge (other) (cosmology) as well as Lore (Sun spots), and that race has Skill Focus for both, I can bootstrap the feat twice and target it to skKnowOth for one and to skLorOther for the other, but how can I make sure those Skill Focuses are applied to only those two, and not to further Knowledge (other) or Lore picks added to the character?

Create your own Knowledge/Lore skill? instead of using other

Certainly simpler, I guess I'll just do that, thanks!