Sorry, Greg, but your source is misinformed.

The first party to submit breakers for testing in someone else's panel was a Taiwan firm. The first UL knew of the submission was when a crate arrived, packed with breakers and the panels in which to test them. The submission surprised UL, who had never imagined someone would do such a thing. Someone saw the Square D panels and asked Square D what was going on.

When Square D heard of the submission, the lobbying began. UL decided to 'throw a bone' by inventing the 'classified' term, just to sooth Square D's anger at the thought of use of the term 'listed'.

Little did UL realize the extent to which the wormtongues at Square D would assert all manner of mystical distinctions between 'listed' and 'classified' products. Such distinctions are patently dishonest. Given the chance to do it all over, I'm sure UL would have simply "listed" the breakers.

When you box them in on this point, Square D's fallback is the sticker that says 'use only Square D parts.' This, they insist, is part of the listing and labeling. To support this, there's no shortage of (erroneous) UL statements saying that everything that comes on or with a product is part of the listing and labeling.

That is simply not true. UL may require certain statements on the product, or supplied with the product, but UL does not control EVERY such statement. For example, in "owners' manuals," about the only statement relevant to UL is the one that says "use in accordance with the NEC."

I don't want to get this thread too far off track; I just want to be clear as to why I don't include replacement breakers in the 'forbidden parts' category.