You’re right, users now can’t create tags (don’t hesitate to ask for new ones to be added)
Currently the following tags exists:
haxe-cs, haxe-js, haxe-swf, haxe-neko, haxe-java, haxe-php, haxe-cpp, haxe-hl, haxe-as3, haxe-cppia, haxe-python, haxe-lua, game, extern, generic, library-showcase, server, merchandise, mobile, web, project-showcase, raspberrypi, macro, ide, cli, linux, windows, osx, type-parameter, reflection, dce, documentation, haxelib, std, debugging, hxml, async.
Which should be enough 