np,
Just go to the relationship and create a summary Checkbox if there are any Enrollments, call it perhaps [Housing is Booked?].
The create a report called "Used on Enrollments" which will have the preferred sort and columns for your drop down list of housings and filer it where [Housing is Booked?] is unchecked.
The go to the FORM properties and set the drop down field to use that report instead of the standard Record Picker.
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Mark Shnier (Your Quickbase Coach)
mark.shnier@gmail.com
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