Separate CM, CMR and CMP jacket marking from Cat performance ratings in surplus data cable.
Checkable specification fields
These are examples from the named references, not assertions about a reel you have not shown us. Match the actual jacket, tag and part number before using a product claim.
| Field | Documented example / boundary | Source |
|---|---|---|
| CM | Belden explains CM as general-purpose communications cable marking. | [1] |
| CMR | Belden distinguishes the riser classification for limiting fire spread between floors. | [1] |
| CMP | Belden distinguishes a separate plenum classification; do not apply it to a CM-only lot. | [1] |
| Concrete example | Belden 7814A publishes Cat 6/250 MHz with a CM designation and PVC jacket; the category does not make it CMP. | [2] |
Read the jacket, reel and current sheet
A seller should transcribe the whole fire-class wording and product number, then match the exact manufacturer document. Belden’s jacket-marking explainer also shows that conductor AWG, pair count and temperature may be printed separately. A faded or partial CM/CMR/CMP legend warrants an “unverified classification” note, not an upgraded label.
- Capture the entire jacket legend, UL reference and reel/box label.
- Keep category (e.g. Cat 6), shielding and CM/CMR/CMP as separate fields.
- Do not copy a temperature or LP/PoE example to another part number.
Condition and project decisions are separate
The printed classification does not prove an aged, opened or previously installed lot’s condition or suitability for a particular building. Report packaging, remaining length, visible damage and any independent tests as separate evidence, leaving installation requirements to the buyer’s qualified review.
- Avoid blanket code compliance, plenum, PoE or buyer-acceptance claims.
- When no complete original marking exists, request the maker’s exact part documentation before a product-level description.
Source notes and scope
The linked references support the specific examples above. Product designs and standards can change; seller-supplied markings, measured length and current condition require separate verification. Nothing here states that this buyer stocks, tests, guarantees or accepts a particular cable, or offers installation advice.