Have you ever gotten a bunch of different strengths of Rigotti reeds mixed up. Maybe you had some 3 lights, 3 mediums and 3 strongs mixed together and no longer had any way to tell them apart since they all looked the same? There is a secret code to tell them apart!! Ok, maybe it's not so secret, but no one has ever written about it before.
Here it is:
Strong reeds have the D filled in with ink.
Light reeds have the O in the word Gold filled in with ink