This module is used to automatically assign terms to a node. The module searches for the terms in the node and assigns them as it finds them.
For more information please check out the MO Auto add terms page.
The module is fully functional for Drupal 6.
We now offer this module here so maybe someone will come in and make it work with Drupal 7...
I put a Demo link that will send you to a taxonomy_vtn site index. When you then click on one of the terms, you are then sent to a list of all the nodes that include that term. As you will see with most terms, the list is quite extensive. This is because MO Auto-Add Terms scans all the nodes as you modify them and re-assign the terms appropriately. Otherwise, the index would definitively not be this complete.
Previous versions of the module were named mo_autoaddterms. If you want to update with this version, make sure to completely uninstall the old version (1.13 and older) and then install this one.
At this point there is no update path. If you did not have any particular settings (hidden term) then it should be easy to setup the module anew.
On the other hand, if you need to upgrade, you just have to rename the tables with mo_auto_add_terms instead of mo_autoaddterms. Look at the install script for more info about the tables. First, uninstall the older version (1.13-), do the renaming, then install the new version (1.14+).