Hi,
I created a new category for contributions, and renamed/moved the old one to "Old contributions (archive)".
The old one is shown at the top of the contributions category.
I moved to the new contributions category all the topics which were not yet processed.
New contributions:
http://forum.imcdb.org/forum_category-8-Contributions.html
Archive:
http://forum.imcdb.org/forum_category-1-Old_contributions_archive.html
Now when admins have finished to processed a topic, if no additional comment is required, it can be moved to the archive. If some comments/questions are pending, it is better to wait before doing that (eventually you can still add the "[done]" in the title)
Note to admin: to move a topic, click on the following icon at the top right corner of the page showing the topic messages: