Tom Neff wrote, | Fourth, say hello to the pass-through problem. When one list feeds | another, the originating List-ID should survive, according to the RFC.
I haven't seen the RFC, but I saw some drafts and had some correspondence with the proposers. The language like that in the drafts meant that a downstream list that exists solely as an exploder and originates no content of its own should leave List-ID unchanged. When the downstream list carries the entire content of the upstream list but also originates content of its own that is not distributed to people who belong only to the upstream list, it wasn't so cut-and-dried. Certainly the material originating in the downstream list should have a different List-ID from that on posts coming out of the upstream list; whether the downstream list should change the List-ID on articles from the upstream list as it propagates them (or add its own while leaving the original present as well) was not clear and perhaps dependent on details of the situation. If the downstream list carries selected content from the upstream list (even if it adds none of its own), that's yet another case. If the RFC made it seem simple and set in stone, then that's a change from the drafts.
