Birmingham 911 District
I Googled "What is Birmingham 911 District" and did not come up with anything.
I found this information attached to the FCC license. This license just was processed in July.
BIRMINGHAM 911 DISTRICT
712 19TH STREET NORTH
BIRMINGHAM, AL 35203
ATTN GREG SILAS
Greg Silas works for the City of B'ham - 911 Director. I'm guessing that since he is involved this may be a Smart Zone addition to improve coverage for B'ham and Jeff County radios. Just guessing.