What must uucp names be limited to 7 characters?

[Dave Martindale]

The names of the local and remote systems are used in building the
names of the various spool files.  On most UNIX systems, file names
are limited to 14 characters, and there are 7 characters of other junk
wrapped around the system name to make up a total of 14.
("D." or "C." or "X." and a "grade of service" character and a 4-character
sequence number).

A public domain uucp will appear whenever someone writes one and gives
it away - probably never.  It is quite a substantial job, since the protocol
used at the bottom level is both complex and mostly undocumented.
I know of only one person (Lauren) who has written a uucp from scratch,
and I don't believe he intends to give it away, having been bitten by putting
software into the public domain before.