Sonny one of my air compressor motors has the special VFD wire inside it..it's a mid-90's vintage 5HP Baldor..just went past it this AM and thought of what we had been talking about
[Linked Image from kuhnbros.com]

Ive wired plenty of motors without this internal wire, but if I had my choice in spec-ing out a motor for a VFD I'd choose it..air compressors with start/stop duty don't need it.