It depends on the year model of the Jeep as to what you do.
The following is stole...eh...borrowed from JP Magazine
older cj / fsj up to 1979 with the spicer / Dana 18 or 20 can be towed with the t-case in neutral, transmission in gear.
76-79 cj / fsj with the quadra-trac CAN NOT be towed...
I hope this thread is not too old lol. I found it while doing a google search as my t-case has the exact shift pattern as the original poster. I'm trying to learn more about it as I plan to flat tow my Jeep and I'm looking for the proper way to do so.