Available Locations

This field will contain a list of  active  Locations (as defined on the Admin >> Setup >> Locations screen) that are not currently associated with this record.

Note regarding inactive Locations:  Locations that have been set to a status of "Inactive" will not show up in the left "Available Locations" window.  They will, however, show up in the right "Locations For" window.  In this way, you can un-assign a disabled location if you would like.  By default, the locations will remain associated even if they are set to a status of inactive.

This list can be populated / refined using the Filter feature.