System views in all_tab_comments

Matt Penny posted about extracting a crib-sheet for the DBA_ views from the online documentation.

I can't find a comment link on his article, but he could have got most of that information from the database:

select * from all_tab_comments
where comments is not null
and table_name like 'DBA_%';

Yes, you can but comments on views as well as tables and columns. In fact in 11gR2 you can comment on editions, operators (but not procedures and functions) materialized views, index types and 'mining models' (though I have no idea what the latter is).