A business card under the lid of uprights, or lying on the plate under the music desk of grands with tuning dates and temperature/humidity readings entered on the back does three things. It identifies the perpetrator of the last tuning. It acts as a running long term history of maintenance and climate (I never take the old cards out). And last of all, it often disappears, rendering all of the above useless. Therefor, a stealth sticker of some sort on the underside of the music desk in grands, and on the back side of the front board of verticals, will retain the history without the owner (and quite likely any subsequent tuner) ever being aware it's even there. No, it's not a mindless macho male marking of territory, nor a scribbling defacement of the treasured ancestral photo gallery display stand. It's an attempt to retain diagnostic information with the piano for the benefit of both the owner, and this year's tech (should he/she notice), in spite of peoples' insistence on taking the cards out and losing the information. How many pianos do you suppose you have tuned that had a sticker on the underside of the music desk, or the back side of the front board, that you didn't notice even when you had the thing apart?
This PTG archive page provided courtesy of Moy Piano Service, LLC