Patch-By-Exception was originally brought out by Krone, however, other data cabling product vendors are also adopting this concept in their product line.

Traditionally, comms (mainly telephones) was patched by running jumper wires between two IDC blocks, and before then was done either by soldering jumper onto tags or wirewrapping onto thin posts using a wire wrap tool. Data patching was done using a length of patch cord with the appropiate data connection plugs on each end, nowdays, it is RJ-45, but is not limited to that.

Both methods of patching had their merits, which included costs (both capital and maintainence), space requirements, usablity, and visual appearence.

Patch-by-Exception is designed to have the tidiness and cost savings of a jumper type patch panel, but also have the flexibilty and ease of adds/moves/changes of traditonal data patch panel.

Disconnect blocks are used so that when a Patch-By-Exception patch cord is plugged in, the jumper patch has been disconnected and is no longer an active patch. This means a premises can be patched using the appropiate jumper cable, but if changes needs to be made (very handy for temporary situations) then a special patch cord can be inserted between two IDC blocks to make that patch active.