Simplify the following text for a Grade 6 native English-speaking person.
Original: The following alpha-3 codes can be user-assigned : from AAA to AAZ , from QMA to QZZ , from XAA to XZZ , and from ZZA to ZZZ .
Simplified: The following alpha-3 codes can be user-assigned : AAA to AAZ , QMA to QZZ , XAA to XZZ , and ZZA to ZZZ .