A local mechanic here in Savannah marks the valve cover in some way just in case a customer claims a valve inspection wasn't done.
When I did mine last year, I put my initials and mileage with a permanent marker inside the valve cover (who knows if it will be there next time?).
For comparison, one of the local Kawasaki dealers cannot possibly do valve inspections. Not only do they not have the proper shims, they do not have a micrometer. Many shims markings are unreadable, in these cases a micrometer is necessary to determine the thickness so the proper calculation can be made to get the proper clearance.
When asked, the mechanic simply said "I haven't needed a micrometer in 3 years".
Either he's very good at guessing differences of .00x" or he's a knucklehead who is charging customers for work that is not performed.
YMMV.