I'm a little confused with this F74 code. In the Participant Statistical Areas Program (PSAP) documentation it says that boundaries coded F74 are "unacceptable" features on land but "acceptable" features in water (page 63). My TIGER 97 lines on my GIS show red (F74 codes) all over the place in bodies of water but they were not identified as unacceptable boundary features on the paper maps provided by the Census Bureau for the PSAP. Will TAZ-UP differenciate between F74s on land and F74s in water. I used several F74 boundaries in water to define census tracts and blockgroups for the PSAP. I was even told I could add them if necessary. If we can't use F74s in water, I'll have a bunch of long rat tails at the end of my zones because I can't cut across the river until the next bridge, dam, etc. Let me know what you think. Todd A. Steiss