I believe that phpBB should have the ability to set permissions for who can use custom bbcodes. This would be very useful because you can have certain bbcodes for admins/moderators etc. This would also mean you could hide bbcodes to logged in users, as you could have permissions for viewing and using etc.
- More control on what content can be displayed in posts
- Can hide comments for moderators/admins
- Saves heavy modding by authors to achieve hiding content from guests etc
- Alot of code change to get this to work
- Alot of new permissions would be added - may get confussing
To make this less confussing I would suggest being able to assign bbcodes into groups e.g.
- Create a bbcode group called 'Admins'
- Add the bbcodes into this group that the admins will be able to use
- Then in the permissions system you have an option 'Can use bbcode group Admins' and 'Can view bbcode group Admins'
- When posting only the bbcodes you can use display in the posting area
- If you try to use a bbcode you do not have permission to use it removes the tags from the post and just puts the text.
A way to stop people getting confussed as to why their bbcode isn't showing, would be if a bbcode isn't assigned into a group it will automatically show on the posting page, this means if people don't want to use this system it still works the old way.
I did have a working copy of something like this ages ago so I know it is possible, I think this would be a very useful feature to be added as it would be use by a lot of people.