Any cord that is likely to be used regularly outdoors, or in a wet location, should be marked with a “W”, as in SJTW. The “W” mark added to the wire description means that the insulation and jacket have been approved for use in the sunlight and in wet locations. Some people may remember years ago when these markings were separately added to the cord marking on the jacket. Harmonization of standards in North America has resolved this issue and all cords now meet the same requirement when marked with the “W”. All cords must meet a flame test and are marked FT-2 on the jacket. This is added safety for all cords as a result of standards improvement by Underwriters Laboratories and Canadian Standards Association.