It is not clear how the bot is handling the deprecated "coauthors" parameter (in most cases, it seems to convert "coauthor(s)" to "author2"), but that may be part of the issue.

Current thinking: identify when the author list is comma-separated and lacks "."s, and put that value (whether in author, authors, coauthor, coauthors) into a new "vauthors" param. The first author appears to be handled as a special case, so that may be leading to some of the instances of extended "author2" parameters.

Posted requesting comment on the citation bot talk page: https://en.wikipedia.org/wiki/User_talk:Citation_bot#Handling_multiple_authors

Current thinking: identify when the author list is comma-separated and lacks "."s, and put that value (whether in author, authors, coauthor, coauthors) into a new "vauthors" param. The first author appears to be handled as a special case, so that may be leading to some of the instances of extended "author2" parameters.

This has three problems. First, vauthors is a list of all authors, whereas coauthor/coauthors is not, so you would have to make sure that you were combining the values from author/first/last/first1/last1 with coauthors (in a way that made sense) before putting them in vauthors. Second, comma separated author lists without periods aren't necessarily Vancouver-style author lists. For example, "Doe, Jane Seymore; Kennedy, John Fitzgerald" is not a Vancouver-style list (which would be "Doe JS, Kennedy JF"). The whole addition of Vancouver-style author lists is a recent addition to the citation templates and made the whole author system even more complicated. Finally, vauthors (Vancouver-style author lists) should only be used in articles where that is the predominant author listing style, not in all articles.

My suggestion is still to remove all author modification capabilities from Citation bot. Yes, this reduces it's functionality, but otherwise we have to support a million different contingencies.

Should've marked that as old. Actual current thinking:

• save initial author parameters in an array on first parsing the cite template.
• when expanding/adding parameters, check whether that array is empty. If it is, go ahead and fetch/expand authors as normal. If it isn't, skip all author parameters (the bot has a list of them) and handle the rest of the citation.

@Fhocutt: That sounds reasonable to me.

Commented asking for testing at the talk page. https://en.wikipedia.org/w/index.php?title=User_talk%3ACitation_bot&type=revision&diff=681567979&oldid=681378885

Known issues:

• Will still modify editors, regardless of whether editor name parameters are present. Unclear whether this needs to be changed for bot unblocking.

Everything else should be as desired.

Most recent test page diff: https://test.wikipedia.org/w/index.php?title=User%3AFhocutt_%28WMF%29%2FSandbox&type=revision&diff=242480&oldid=242479

Will still modify editors, regardless of whether editor name parameters are present. Unclear whether this needs to be changed for bot unblocking.

@Fhocutt: Can you elaborate on this? Do you know what conditions it happens in?

@kaldari: looking at the code, this actually doesn't seem to happen--it'll already add editors only if the first editor is blank (in Template::add_if_new()), and it looks like it doesn't overwrite elsewhere.