Some mostly minor corrections:
In the beginning, comics were just themselves (no additional versions/editions). A significant majority, but not all, were distributed through the newsstand system.
Comic shop owners ordered from distributors, not publishers.
"The barcode area on the cover would soon become a consistent way to identify newsstand and direct edition comic books." "Barcode lines in the 1980s identify a newsstand edition." Usually, but this is not guaranteed.
Marvel's 'M' box was only in use from Oct 82 - Mar 87, just over 4 years.
Many comics, even from the Big 2, distributed through the direct market during the dual distribution era do not have Newsstand editions.