WW wrote:
What is the difference between NM and NMB romex cable? Code here now will
not allow NM to be used. WW

Plain NM w/o any following designation is the old, original "Romex (tm)"
that used fiber insulation and hence was dry-only application. NM-C
followed w/ the plastic. NM is, for the most part, unavailable.

AFAIK, the "B" designation is for building application and is the
nomenclature for the color-coded sheathing of white/yellow/etc. designed
to aid in ensuring proper conductor size is used in appropriate circuits
and making for easier/quicker verification during inspection.

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