The NEC doesn't explicitly state that the cable jacket itself must state "suitable for wet locations." However, it implicitly requires that the cable be identified for wet locations, and the usual method of identification is through markings on the jacket. Here's the breakdown: Article 310 General Requirements for Conductors for General Wiring



310.10(C) Wet Locations. "...Conductors and cables used in wet locations shall be listed for use in wet locations..." Article 100 Definitions



Identified (as applied to equipment). Recognizable as suitable for the specific purpose, function, use, environment, application, and so forth, where described in a particular Code requirement. Article 300.5(B) Wet Locations (D)(1) RMC, IMC, PVC Conduit, or Reinforced Thermosetting Resin Conduit (RTRC). All conductors installed in raceways shall be listed as suitable for use in wet locations. (E) Cables and Insulated Conductors. Cables and insulated conductors installed in enclosures or raceways in underground installations shall be listed for use in wet locations. Article 334 Nonmetallic-Sheathed Cable: Type NM, Type NMC, and Type NMS 334.12 Uses Not Permitted. (B)(4) Where exposed or subject to physical damage (B)(5) In wet or damp locations Article 334.10 Uses Permitted (3) Type NMC. Type NMC is permitted as follows: (1) For both exposed and concealed work in dry, moist, damp, or corrosive locations, except as prohibited in 334.12. (2) In outside and inside walls of masonry block or tile. (3) In a shallow chase in masonry, concrete, or adobe protected against nails or screws by a steel plate at least 1.59 mm (1/16 in.) thick and covered with plaster, adobe, or similar finishIn summary

The NEC mandates that cables used in wet locations must be

listed for such use (310.10(C)). "Listed" means tested and approved by a recognized testing laboratory (like UL) and bearing their listing mark. "Identified" means recognizable as suitable for that use. While the NEC does not explicitly state that the cable jacket must have markings, in practice, the usual way to identify a cable as being listed and suitable for wet locations is through markings on the jacket indicating its wet-location rating (e.g., "Suitable for Wet Locations," or a specific designation like "USE," "THWN," or "XHHW"). Without such markings, an inspector would have no way to verify that the cable is indeed listed for wet locations.

Example of Markings

Common examples of markings on cable jackets that indicate suitability for wet locations include:

"USE" or "USE-2"

Underground Service Entrance cable, generally suitable for wet locations.

"THWN" or "THWN-2"

Thermoplastic High Water/Heat-resistant Nylon-covered wire. The "W" indicates wet location suitability.

"XHHW" or "XHHW-2"

Cross-linked Polyethylene High Heat Water-resistant wire. The "W" indicates wet location suitability.

"Wet Locations": Some cable jackets will explicitly state this.Therefore, while the NEC focuses on the listing and identification* requirements, the practical application relies on markings on the cable jacket to demonstrate that the cable meets those requirements. Inspectors will look for these markings to confirm that the correct cable is being used in the correct location. Flag for review