Careers have 8 skills, and you get a free rank in each of them.
Specializations have 4 skills, and you get a free rank in two of them.
If you have a skill that is duplicated between the career and specialization, you can choose to spend one rank from each side to start with that skill at rank 2.
Is there any other benefit to having the same skill in both career and specialization? There doesn't seem to be any that I can find, which means that in effect if you don't decide to put two ranks into that particular skill, you'll only start with 11 (or even fewer) career skills.
Which is fine - I understand that specializations aren't just about the career since you can cross over. Just want to make sure I'm not missing anything.