those sticky dots are like what they use for beginning Suzuki violin students to put on their finger board to tell where to put their fingers. Those Avery labels can be found in any stationery/office equipment or variety store. I also solved a similar porblem with my auto harp which has labels on the chord bars which can only be seen from above when playing it flat on a tqable or your lap infrom=nt of you.
if you hold it up "mother Maybelle" style, you can no longer see them. I used a label maker...one of those punch type wheelie deals where you spin the alphabet template around and squeeze the trigger to stamp the letters into sticky plastic strip which then affixes to whatever you want to label. you could use one of those and just punch out a "period" or "zero" or even no letter at all, just a square shape the size of one character. perhaps there is one of those around the ranger shop to label binoculars, etc.