:FidoNet: n. A worldwide hobbyist network of personal computers
which exchanges mail, discussion groups, and files. Founded in 1984
and originally consisting only of IBM PCs and compatibles, FidoNet
now includes such diverse machines as Apple ][s, Ataris, Amigas,
and UNIX systems. Though it is much younger than {USENET},
FidoNet is already (in early 1991) a significant fraction of
USENET's size at some 8000 systems.
-- The AI Hackers Dictionary
dup loop: /d[y]oop loop/ (also `dupe loop') [FidoNet] n. An
infinite stream of duplicated, near-identical messages on a FidoNet
{echo}, the only difference being unique or mangled identification
information applied by a faulty or incorrectly configured system or
network gateway, thus rendering {dup killer}s ineffective....