This has bothered me for a long time. French braid is being used as a catch all tag for braids that start higher than a regular braided ponytail or side braid. It's like calling a pear a green apple and a plum a purple apple; generic term "fruit" would be "braid". True French braids are nearly nonexistent on Danbooru.
Rare example: post #5893969 braid takes a wide portion from top to bottom of head, though the ponytail itself isn't braided.
Most of these posts should be tagged as one of the following:
- braided bun (bun itself may be braided or otherwise have a braid wrapped around it)
- crown braid (currently includes hairband-like braids)
- half updo
Half up French braid exists but keep in mind the braid takes up a larger portion of hair around the crown and don't appear "loose" like the usual half updo. By "loose" I mean the base of regular braids appear to come from a single point as opposed to pulling from all scalp against the braid.
Side braids of Baltimore (Azur Lane) and Ai-chan (Tawawa) are ambiguous and officially drawn behind the ears, but don't quite look like something like this (example of somewhat narrow French braid). One factor could be that anime drawings are less detailed than real life.
Odd variants. post #5900947 braid runs back and ends into a regular ponytail. post #5909859 braid runs into whatever this is (single-coiled hair ring in some of her posts). For now Yuzu (Blue Archive) is just one_side_up braid.
Side note: I have no opinion on these but creating new tags braided_half_updo and braided_hair_rings may be plausible unless we feel like this is too many braid-related tags.