Usually
standards are a super-set because the Standard did not support 'x'
IEEE488=>HPIB (in this case, the standard, was made AFTERWARDS)
How many extensions of BASIC were there? Pascal? Fortran? (those I have used)
'EPUB' versions seem to leave out big chunks or fail to do them properly.
Some you might blame on being part of the first generation e-books. But by EPUB2, those should have dwindled to a tiny-tiny list.
not so
