[applicative]

There have been theoretically precise published specs for serious markdowns for 15 years. The commonmark convention is a common specification for many including e.g the familiar simple github variant, which emphatically does have a completely perfect specification.

[harshreality]

Commonmark isn't serious because it doesn't include several major quality of life improvements like [^1] for footnote/reference syntax. Pandoc should be the serious "common" markdown standard.

[applicative]

It is perfectly serious, though hobbled by various recalcitrant forces. For example, if I write using only ye olde original markdown devices, pandoc will render as it would commonmark. The core commonmark idea is to have an unambiguous specification of /the original syntax/ -- which emphatically didnt exist: the perl regex script was the only actual specification.

Part of the problem is that people want to say 'markdown' but John Gruber, pissing on the corpse of Aaron Schwarz, falsely claims total possession of everything that comes under that head, and that there must be no independent specification. This simple fact totally destroys the entire milieu. 80% of complaints about 'markdown' are due to his recalcitrance. Thus there can be no spec, no spec specifying extensions, etc. He does not want anything like html to be defined as he will lose ... I'm not sure what, since he is deeply evil, as this one case shows with total clarity. Industrial interests would be enough to get an html-like convention if it were otherwise.