In my aircraft (HS-125) it's not defined in the AFM but our company does have stated limits in our Ops manual which are applicable to all the different types we operate.
To expand my question a bit, as you've rightly said, these limits should type specific, but in the absence of any AFM guidance is there an industry standard or EU-Ops (or FAA) recommendation ? For example, 1/2 the max dry runway xwind limit for med-good braking action, 1/4 for medium, 1/8 med-poor etc etc (I've made those numbers up).
Thanks
Buzz