Settle the numbering scheme before you print anything
The scheme is the decision; the labels are just its output. Two properties make a scheme last.
It has to be stable against renaming. A study becomes a nursery, a spare room becomes an office, and a panel labelled with room names becomes wrong without anybody touching a cable. A scheme built from a floor and a sequence — the position in the building rather than its current use — stays true.
It has to be readable in both directions. Standing at a faceplate, you should be able to work out which panel port it lands on; standing at the panel, you should be able to work out which faceplate to walk to. That means the identifier lives at both ends and is identical at both ends, with no translation table in between.
A simple form that satisfies both: a floor indicator, a sequence number, and where a room has several outlets, a letter for the position within it. Whatever you choose, choose it once and apply it to every run in the building, including the ones added later.
Put the identifier on the cable jacket, not only in the panel window
Panel windows and faceplate labels are the labels you read. The label that saves you is the one written in permanent marker directly on the cable jacket, a short distance behind each termination.
The reason is that windows and clip-in labels are attached to the hardware rather than to the cable. Replace a faceplate, swap a panel, or pull a bundle out to work behind it, and the labels stay with the parts while the cables move. Ink on the jacket moves with the cable.
Write it at both ends, and write it before you terminate, while the cable is still loose in your hand and the identifier is still what you think it is.
Number the panel to match the building, and print the map immediately
When the panel is populated, fill in the ports in an order that walks the building — ground floor first, then up, and within a floor in a consistent direction. A panel numbered in the order that the installer happened to reach each cable is a panel that has to be read one label at a time.
Then make the map while the information is still in your head: a printed page listing each panel port, the room and position it serves, and what is currently plugged into it. Not a file on a machine that lives on this network — a printed page, taped inside the cabinet door.
The map is the artefact that makes the cabinet self-explanatory to somebody who has never seen it, and that somebody is frequently you, in a hurry, after a power cut.
Colour the leads by job, and write the code on the door
Colour does not affect how a lead performs, and it does an enormous amount for how quickly a cabinet can be read. A workable code uses very few categories:
- one colour for uplinks — anything carrying traffic between the cabinet and the rest of the network;
- one for ports that feed powered devices over the cable, so that nobody unplugs a ceiling access point wondering why it went dark;
- one for everything ordinary.
More categories than that stop being memorable. Whatever you settle on, the code goes on the printed map and on the door, because the person who needs it is the person who did not invent it.
Dress the leads for the next change, not for a photograph
The temptation with a new cabinet is to bundle everything into a single immaculate loom. That looks superb and it makes every subsequent change a job of cutting ties and rebuilding.
Dress for maintenance instead. Run leads in small groups rather than one bundle, route them through the cable management the cabinet provides, and leave enough slack at each end that a lead can be moved a few ports without being replaced.
Fasten with hook-and-loop wraps done up loosely, not with plastic ties pulled tight. This is not only about future changes: a tie tightened enough to dent the jacket has changed the spacing of the pairs inside it, and the geometry of those pairs is what the category grade depends on. Keep the same discipline about bend radius that applies to the fixed runs — the tightest bend in most installations is behind a panel, where somebody has forced the slack into a space that will not take it.
Leave a spare port, a spare lead and a blank panel
Three small provisions make a cabinet pleasant to live with. A spare port on the switch, so that adding a device does not mean displacing one. A couple of spare leads of the right lengths hanging inside the door, so that a change never waits on an order. And a blanking panel over any unused rack space, which keeps airflow going where the cabinet intends it to.
Leave a rack unit of clearance above anything that runs warm, and read what the maker specifies about clearance and ventilation before deciding where the cabinet itself goes. A cabinet in a cupboard is a different thermal problem from the same cabinet in a hallway.
Photograph the cabinet before you close the door
Take a clear photograph of the front of the panel and the switch with everything plugged in, and another of the back. Keep them somewhere that is not on this network.
It costs ten seconds and it answers the question that comes up most often after an emergency: what was plugged in where, before somebody started pulling things out to find the problem.
What belongs to somebody else
Any socket added inside or beside the cabinet, any spur, and the earthing of a metal enclosure are governed by the manufacturer’s instructions and by the wiring rules that apply where you live. Work out what the equipment needs, then hand those requirements to somebody qualified to carry them out.
The questions that come up before an order
Is a handwritten label good enough?
It is, provided it is in permanent marker and it is on the cable as well as in the panel window. What fails is not the handwriting but the medium: sticky paper labels curl off jackets within a couple of years, and a label that has fallen into the bottom of a cabinet is the same as no label at all.
How should I number the ports?
In an order that describes the building rather than the order you happened to terminate them in, and with a scheme that does not embed anything that could change. Room names change when a study becomes a bedroom; a floor and a sequence number do not.
Do I need to colour-code the patch leads?
Not for correctness, but it is the fastest way to make a cabinet readable at a glance — one colour for uplinks, one for ports feeding powered devices, one for everything ordinary. The rule is to write the code on the cabinet door, because a code nobody can look up is decoration.
Last reviewed 10 September 2026
