Above and below the 'leash' the numbers for the right hand and the left hand. Cross lines are repeat signs, a 'roof' indicates bellows direction of pressure, a 'tub' direction of pull. Graf on this (p.179): "A. Schuch writes in his bandonion school (1890), he wants "do not bother the student with any theoretical stuff from the outset, but immediately start with practical employ and educate! Besides, the nature of the instrument, where each tone is designated by the number anyway, take a temporary distance... from any study of sheet music."
However, the spread of the tabulator showed that there was a permanent withdrawal from the note study.