I answered "no" only because I don't have any. I intend to get several in different sizes, if I can, to fit each of my flintlocks, but haven't gotten around to measuring them all yet.
While that statement is a gold standard for manual of arms safety, there are some guns that ONLY have half-**** and nothing else. I always test half-**** before loading by both pressing the trigger and pushing on the hammer (or the ****, as applicable to lock type).....
Also, one should NEVER rely solely on the half **** notch, on ANY gun.