Hello folks. Apparently Drive-Thru RPG underwent some organization changes, namely in the D&D/D20 department.
Now they have a primary Rules System tag: D&D/D20.
And these are the sub-category tags:
Dungeons & Dragons (Third-Party) and Dungeons & Dragons (Official). The categories below are more or less identical save for the option in parenthesis:
3x D&D/d20/OGL (Third-Party/Official)
5e/D&D Next (Third-Party/Official)
4e D&D/GSL (Third-Party/Official)
Basic/BECMI and OD&D (Third-Party/Official)
2e AD&D (Third-Party/Official)
1e AD&D (Third-Party/Official)
So I decided to browse some popular products which used to be part of the OSR:
Sword of Air is now D&D/D20
Silent Legions is now D&D/D20
Spears of the Dawn is not organized under any tags at all
White Star is just OSRIC and D&D/D20
Ambition & Avarice has no category or tags
Barrowmaze Complete is OSRIC and Labyrinth Lord, but not D&D/D20
If you read this post, please spread the word. Whether you be a fan or publisher, it's possible that products you published or had your eye on are now categorized differently. OSRIC and Labyrinth Lord still have their own categories, but given that there are many games which fall outside this purview this leaves many others in the dust or under the generic D&D/D20 label.