Looking at Harrison County in the database, I see several of the casinos and resorts are using either DMR or NXDN. There are also several DMR channels in use by the Biloxi school district.
I'm very familiar with the Harrison County section on RR. I've submitted most of the info for the county. All casinos use either DMR or NXDN with the exception of Boomtown, which is still using LTR, and 2 other Casinos (Palace & Golden Nugget) are still using Analog Conventional frequencies.
There is only 1 DMR frequency for the Biloxi Public Schools, which is a DMR1F system used by the High School and Junior High. All the other BPS schools use analog conventional. These I've also submitted since I'm a BPS employee.
There are tons more businesses that I've found over the years that are sometimes interesting to listen to. There's only 1 that has me completely stumped as to how it works, the Biloxi Grand Casino (now Harrahs, I think) that uses XPT and have never been able to get usable LCN's for it. That one is not submitted yet, but I just put 5 sites in with 1 frequency in each site, and it's about 75% working.
If you live in Long Beach, you are very close to Hancock county too, especially Bay St. Louis. Hollywood casino is there, but I don't get over there very much, but they have a 5 frequency CAP site there. I have yet to submit this one.
I'm glad someone corrected me, I forgot about the other 4 scanners that can pick up provoice besides the 436/536. I had a SDS100 when they first came out, but had to sell it due to a financial situation. Hope to get another one as soon as I can afford it.
Hope this info helps, if you need any help setting up Harrison County, let me know.