I thought players announced their ball and marking on the 1st tee?
This is not required at all under the Rules of Golf. Nor do you have to announce to the group when you're changing balls, markings, etc.
You only have to be able to identify your own golf ball.
On the first tee, the starter will commonly say "gentlemen, please identify your ball and markings" as he is reading the local rules etc.
It may not be a
rule of golf, but I defy anyone to not hold up their ball and state the brand, number and markings after being asked to do so in front of the group.
And sure, I technically need merely to be able to identify my ball, but those not of the Reed ilk(as in nearly all), will announce the number and markings on a provisional, to distinguish it from the original.To keep that simple, most will stick with the same number they began with and declared on 1 tee, or, if switching numbers, let someone, preferably their marker, in the group know.
So you're both right-not a rule, but a custom.
I've gone so far as to use different color markers for a tournament round if I lost balls during the practice round.