What does it mean that a workshop has proceedings in the main conference?

Question

In my (short) research experience I have come across workshops whose main track either (1) has its own proceedings (outside the main conference with which it is co-located) or (2) has no proceedings at all.

But recently I have come across one that says, verbatim: Please note that due to the tight timeline to have accepted papers included in the main_conference_name proceedings, no supplemental materials or rebuttal will be accepted.

What exactly does this mean? Does it mean that the paper, despite belonging to the workshop, is considered to be "from the category of the main conference with which it is co-located"? Or is it just a formalism to say the same as case 1 (own proceedings)? I assume that it is the latter, but I am interested in the answer because the main conference has a good score with respect to http://portal.core.edu.au/conf-ranks/

I searched in Stack Exchange and found the post What is " companion proceedings" in a conference?, where the answer distinguishes between main proceedings and companion proceedings, but this is not clarified within the page of the workshop...

Answer 1

Based on the context, I am assuming you are referring to workshops and conferences in computer science. The following is based on what I have seen in the subfields of machine learning and computer vision, so I cannot be certain how generally it applies.

A conference will generally have several workshops co-located with it, and several of them (but probably not all) will have formally published proceedings. The proceedings of all such workshops associated with the conference are published in a separate set of volumes called something along the lines of "Proceedings of <Main Conference Name> Workshops, <Year>". For example, here are the Proceedings of ECCV 2022, and here are the Proceedings of ECCV 2022 Workshops.

So, most likely it refers to the Workshop Proceedings of the main conference. (Caveat: some conferences have multiple tracks, all of which are published in the main proceedings, I am assuming this is not the case here). In such cases, generally "Proceedings of <Main Conference Name> Workshops, <Year>" will also be what is used as the venue when citing the paper. Being published in the workshop proceedings of a top-tier conference does give the paper good visibility, but it is not the same (often, also in terms of expected contributions, prestige, etc.) as being accepted in the main conference.