I bit the bullet and went through all 100-odd guitar
music publications I've
collected over the years, from publishers around the
world on every continent,
across multiple genres (although admittedly mostly
classical and South
American). The set includes many volumes whose purpose
is purely
didactic. And yet I was only able to find three books
that use this notation.
So I suspect that "standard" isn't exactly the right
word to use here. :-)
It's probably better to say that it's the "correct" way
of guitar notation -- one
that is satisfying from a theoretician's standpoint,
but rarely used in practice.