weegee the “everyone” and “members” groups can be given permissions, just like any other group - but not all permissions support all groups (for example, posting requires you to have an account, so you can’t set that permission to “everyone” - that is, without using an extension that adds guest posts or similar concept). Example (from Admin > Permissions):
Read more about Flarum permissions here (may include more technical stuff too): https://docs.flarum.org/extend/permissions/
