The only time I have ever had a customer say anything about labels it was because I forgot to put one one. No one has ever asked for a date when it should be strung but several times they specifically want to know when it was strung. They want to determine for themselves when it should be strung. The only thing I put of the label is string type, tension, and date. If you have trouble getting the labels off you can always put them on the blue painters tape.
I have the ability to drive people crazy, not sure if I was born with it or I learned it but I'm damn good at it.