Stating that "[a]s to strength of a mark . . . [third-party] registration evidence may not be given any weight . . . [because they are] not evidence of what happens in the market place"
In Wincharger Corp. v. Rinco, Inc., 297 F.2d 261 (C.C.P.A. 1962), for example, which concerned the sophistication of technicians in the field of electrical devices, the court stated that while technicians are "a discriminating group of people [b]eing skilled in their own art does not necessarily preclude their mistaking one trademark for another...."