How may amateurs use the 219 to 220 MHz segment of 1.25 meter band?

The 1.25-meter amateur band in the United States is split into different segments. While the main segment for voice and general use spans from 222 to 225 MHz, the lower sliver from 219 to 220 MHz is heavily restricted. Amateurs are allocated this 219 to 220 MHz segment on a secondary basis exclusively for fixed digital message forwarding systems (such as automated packet radio backbones). Amateurs operating here must coordinate their usage to avoid interfering with primary Automated Maritime Telecommunications Systems (AMTS). Because of these strict secondary use rules, options like emergency traffic, fast-scan television, and spread spectrum are strictly prohibited in this specific 1 MHz segment.