If there is any question concerning fault current, most inspectors will require documentation.
(Locally most disjunctions require fault current info on any service 400 amps or larger).
110.22 has requirements for marking of equipment used in both engineered and tested series rated systems.
Briefly a "series-rated" system allows components with a rating less than the system available faulty current to be used as long as they are installed in series with upstream devices that are engineered to work in conjunction.
For example, on a installation with 65k available current, a 10k rated breaker may be designed to be acceptable if it is downstream of a particular breaker or fuse.
Care must be taken as different manufactures do do series rate between each other and each breaker must be looked at on its own terms, for instance, a 2 pole 50 amp breaker might series rate in a particular design whereas a 3 pole 70 won't.
