[HECnet] What are your DAP flag bit definitions?

I was writing a routine to break out DAP flag bits to aid debugging when I noticed a possible discrepancy between DAP V5.6 and Tops-20, viz: DAP Bit Bit Meaning PDP-10 Bit Tops-20 DAP Symbol 0 Stream Identification Field Present 1B35 HD$SID 1 Length Field Present 1B34 HD$LEN 2 Extended Length Field Present 1B33 HD$LN2 3 Bit Count Field Present 1B32 HD$BCT 4 Reserved 1B31 HD$SEG 5 System Specific Field Present 1B30 6 Not last message of segmented message 1B28 DAP V5.6 reserves bit 4 and defines bit 6 to flag that a segmented message is being sent and that this is not the last message.  In other words, that there will be another message. Tops-20 is using bit 4 for this purpose and by rights it would appear that it should be using bit 6. I will go see if I can't scare up what Tops-10 is doing, but I was wondering if anyone knew what other OS's are doing.