TW2013 skill ratings/levels

[Askold]

I'm looking at the rulebook of Twilight 2013 and I'm having some trouble with the terms.

With injuries it is mentioned that they cause a penalty to "skill level" does this mean, for example -1 penalty would drop skill from 9 (professional) to 8 (still professional) or would it go straight from professional to competent?

When discussing using a skill without the qualification and in the example about "led actions" they use the term skill rating in which case it's clearly the novice, competent, professional etc. ratings which directly change the number of dice used when using a skill. And from character creation and character character stat pages I've gotten the impression that the terms are "skill level" and "skill rating" are separate, latter referring to the numerical skill levels.

Then in the example of how injuries work (page 152) a -2 skill level penalty drops skills by two ratings (expert to competent etc.)

How have you guys interpreted these?