IIRC, the sample characters in Basic 3e were all fantasy characters, so likely not. Maybe for Fast-Draw or Survival? Most other skills requiring specializations are higher tech.
We made extensive use of the separate skill list, where which skills requiring specialization was more explicit.
Also, I bought GURPS first for a grittier superhero game, and then for Special Ops. All the
templates sample characters in the latter made it clear about Guns requiring specializations.
(That start probably also made us permanently unwilling to play 100 pt characters.

)
[Edit: Templates were later, dur]