Factorio Forums

"mod-openable" flag in ItemPrototypeFlags says it only works for SelectionToolPrototoype and its children, but it also works for ItemWithTagsPrototype (and maybe others?), as the on_mod_item_opened event does raise when right clicking an item-with-tags with that flag.

Looks like it was changed to work for any item. Thanks for the note, docs updated for 2.0.66.