JSLove@MIT-MULTICS.ARPA ("J. Spencer Love") (09/11/86)
Are, as several have noted, every 10 columns. It is the position of the Multics mailer developers that TAB characters should never be sent over the network, since there is no "standard" width. Thus, all outgoing mail is detabbified, at some slight cost in network throughput. Mail coming in is also detabbified, which affects only non-Multics mail, since there are no tabs in mail leaving Multics. This detabbification *ought* to assume tabs every 8 columns, since this is the de-facto standard. That it doesn't is a bug (to be fair, if the mailer developer had agreed with me, this problem would never have arisen). None of this helps FTP users, since FTP does no TAB transformations. There is, however, a Multics command, "canonicalize", which can insert and remove TAB characters assuming any TAB width, which helps out in some situations. There are other TAB widths in use. I think that Magic 6 uses (used?) a width of 5. The width of 8 is pretty consistent across DEC equipment, but there are other manufacturers out there. There didn't seem to be any consistent use of TABs at all in IBM program products, last I checked. Anyone out there using non-DEC and non-Honeywell gear?