Poster author added me as coauthor after abstract was submitted. Can I include it on CV? Poster author added me as coauthor after its abstract has been submitted to a conference. As a result, on the conference website I'm not listed as an coauthor, but my name is on the actual poster.

Assuming that it's not possible to update poster authorship info on the conference website, should I still list this poster on my CV, or would it just create confusion or misunderstanding?
A poster of which you're not the first author is such a minor thing I wouldn't worry about it (even if it is listed on the conference website).  I don't have a huge publication list but still only include posters I presented (aand only at major conferences).  They don't have anything like the CV impact of a peer-reviewed paper.

Either:


You were accidentally omitted and should be included. In this case the author should contact the conference organisers (but it's probably too late).
Or your contribution was rather minor -- perhaps it only became apparent that your work made it onto the poster at all at the last minute.  In this case while you're named as an author it's closer to an acknowledgement in practice.


Listing it as a publication, if the title can be searched for but you're not named, doesn't seem like a good idea.  Realistically no one is ever going to look.  But if you just happen to come up against someone who's interested in something very specific about the poster that you don't normally do, it isn't going to help you.