Nora Coppo, for all the information provided about Italian manufacture markings.
Andrew Gibson, For providing helpful suggestions on this site.
Bob Berry and the NIA for the info on the unipart "sub divisions" and for photos.
Worldwide Porcelain Insulators (Book By Marilyn Albers and Jack Tod) for drawings of some of the porcelain insulator markings.
Elton Gish for photos and information on US Multiparts & Uniparts.