"The great thing about standards is that there are so many to choose from" - Andrew Tanenbaum
Since the very first concertina tutor (Hoselbarth, c.1840), there have been over 130 tutors published for the Anglo, many with widely differing button numbering and tablature systems. The result of numerous attempts to try to make sense of the Anglo having two notes in different directions for each button, plus having alternate notes on other buttons.
Standard musical notation by itself does not indicate which alternate note or direction is preferable, and since many published tutors print the music an octave high or low, learning actual notes still might not help much, hence the various attempts at tablature systems. Tablature patterns are easily transferable between instruments with different keys, so that's a good thing.
Beginners often buy one or more tutors, only to be faced with having to sort out wildly dissimilar ways of counting buttons and indicating bellows direction.
So.......here, in all its insanity, is a first draft of a notation "Rosetta Stone" translation chart for the 30-button Anglo showing about 30 of the different notating systems.
What an embarrassing gawdawful mess! I know many systems have their adherents and staunch defenders, but could we make it any harder to learn this somewhat intuitive instrument? Pity the poor beginner!