Broadcast PDU type 3

I was interested in getting involved in some open source development. With a signal processing background, I thought osmo-tetra might be a good project. Looking at some data from the New Jersey Transit Authority I noticed something odd though. Some of the Broadcast PDUs had a type of 3, which in the spec is only listed as "Reserved." What's more, the control channels there seem to be missing SYSINFO messages. I'm guessing that somehow their system does a modified SYSINFO (which is normally broadcast type 0) and labels it 3? Is anyone familiar with the format they use for that message? Thanks.