I guess I need help. I have a plugin (not my code, no OSL) that was written for Blender 2.7x and was working well. It was importing and exporting certain game specific mesh formats. Now I am trying to convert that script for my personal use to Blender 2.8x. Never been written some Blender addon at all, so my first attempt. A lot of changes I've done already and the plugin is flawlessly activating/deactivating in Preferences now, which is good. My problem was: I was checking import/export menu (like I am used from Blender 2.7) but the addon doesn't show the options there. First I thought it was not working but I've noticed now it is in the Shift+A menu (where it adds a new type, which is working as well). But it's very unusual to have importer/exporter options in that menu? :) Can someone point me in the right direction why it is doing that and how I can get it in the exporter menu properly?