Service Loop
CSI Division 26, Electrical
A deliberate extra length of slack wire coiled up behind an electrical box or device during rough-in, left there specifically so a future repair, a bad connection, or a device replacement, doesn't come up a few critical inches short.
Why it matters
Once drywall closes a wall in, there's no easy way to pull more wire into a box if the original length turns out to be too short. A service loop is cheap insurance against that problem, costing almost nothing to leave in during rough-in but potentially saving a wall from having to be opened up later.
On a real project
An electrician installing an outlet box leaves several extra inches of slack wire coiled behind the box rather than cutting the wire to the exact minimum length needed, so that if the device ever needs to be reconnected or replaced, there's enough wire to work with.
Who this matters most to
An Electrician builds service loops into rough-in work as standard practice, since it's a small habit that prevents a much bigger problem after walls are finished.
Where this goes wrong
An electrician cuts wire to the bare minimum length needed at every box to save material, with no service loop left behind. When a device later needs to be reconnected after a repair, there isn't enough wire left to work with, and the wall has to be opened up to extend it.