/d[y]oop loop/ (also "dupe loop") [FidoNet] 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 killers} ineffective. If such a duplICate message eventually reaches a system through whICh it has already passed (with the original identifICation information), all systems passed on the way back to that system are said to be involved in a {dup loop}. [Jargon File] (2003-12-15)