In Core Exxet it limits secondary ability bonuses to +100, but I'm not clear from what I read online (and I don't know Spanish) what is included in this +100 limit.

There are at most four things I can think of that would be included towards this limit:

- Characteristic Bonus (from the characteristic itself)

- Innate Bonus (from character class)

- Natural Bonus (equal to characteristic bonus)

- New Core Exxet Bonus (fixed +10s)

Is the +100 limit on the sum of all four of these bonuses? Or on the sum of only some of them?

The +100 bonus is a mix of the +10 and the bonus characteristic. The characteristic bonus is that each level you can choose 2 skills to add their characteristic bonus to, one being a physical skill, and the second being a mental/spiritual skill.

I see. So it's just the sum of the 3rd and 4th in my list that are limited to +100, not the 1st and 2nd?

Say a 5th level wizard had put 100dp into Magic Appraisal (100%), has a Pow 13 (+25), has put 3 natural bonuses into it (+75) and one +10 into it, and as a wizard gets +10/level. His natural bonuses plus 10s is +85, still under the limit, so he has the full magic appraisal of 100+25+85+50 = 260.

Actually other things apply, for instance if you have the advantage that gives you special skill bonus from where you are from. I believe if you specialize in something that goes into special as well.