The 'Ignore list' is a list of waypoints that you have deleted from the database, and that you have indicated that you do not want re-added in a future import. For example, you may have no interest in Virtual Caches, and so you delete them from the database, however, the next time you load a GPX file that includes these caches, they may potentially be re-added to the database.
When you delete a waypoint from the database (see the Delete help topic) you have the option of selecting the Also stop future imports adding this back in check box. Doing so instructs GSAK to add this cache to the 'Ignore list'. When importing a GPX or LOC file GSAK interrogates this list to see if the cache should be added or not. If a cache is on the 'ignore list' it is not added during the import operation.
If you decide later on that you would like this cache to be added into this database you can delete this item from the 'ignore list'. You do this via the menu option Database Þ Maintain Ignore List. GSAK displays the following dialog box:
Click the check boxes beside the caches that you want to remove from the 'ignore list', and click Delete. GSAK deletes them from the 'ignore list', and they will be re-added to the database during the next file import.