So far, I want a field for topical groupings within a collection (I am using Extra for that); one to check off whether or not I have approved a book for the collection; for which floor and shelf in the library. In each case I am using a field that Zotero designates for another purpose. But being able to create my own field, have it display in the table, and be able to sort with it would be very helpful.

I appreciate your input, but I actually don't find the tag function useful for many reasons, the biggest one being that I like to see my collection as a table in which I can see items which have different characteristics together in one place, and sort by those. So tagging is not the solution for me personally. But thanks.

This function is useful for numerous reasons. Primarily for listing preprints (e.g. arXiv, biorXiv) and PubMed codes.

See "eprint" as officially listed in an arXiv instruction (https://arxiv.org/help/hypertex/bibstyles) and Getting DOI / arXiv links with BibTeX (https://www.math.cmu.edu/~gautam/sj/blog/20171114-bibtex-doi.html), as well as some older approaches e.g. mine for giving link to arXiv for Mendeley exports https://gist.github.com/stared/5473014.

Yes, it is a pity that proprietary Mendeley owned by Elsevier provides better support for open archives.

I would add support for this custom field request through the following:

- gender of autor : though it would be charged with a priori (you will not ask every @uthor his gender, it could then give information on your biblio, a value added in gender studies, or to add gender in your variables, etc.
- Improve the possibility to make, print, share, anoted and shared bibliographies: Though there is already a lot to do, it is limited to noting and annotating. The excellent description here https://zotero.hypotheses.org/3556 (in french but still readable tough) show that (see the screen captures at the middle-end of the article). As you might see in this post, things get trickier if you want to tweak around using only the note functionalities. It ends in CSL style editing and invoque other third-party services (Kerko)...
- So I would add fields such as Main hypothesis; methodology; empirical material used, as fields.


Trying to put that in a workflow, here is how it could smoother certain things in some contexts, to my view:
1. When you had an item in your biblio, and/ou make a very short read of it: you want to write a line to describe the item, justifying the import regarding your investigation lines.
2. You do it perfectly well with the current "extra" field, and then set the create form from right click on the item.
3. However, if after a deeper reading you want to sum up the objective of the article, the hypothesis, the method and the type of data use, with some appreciations and comments, and ALSO put it such as it could be clearly outputed from the build inform function, you may want to customized items.
4. After you do this, you would like your colleague to add comments on tops of it.

In sum, I am probably wrong but it is also how monks build manuscript long time ago, through layers of paper file on tops of books. I mean, a good commented biblio facilitates the writing process...

Last to mention, the citavi features enables this with a limit up to 9 fields if I am not wrong. Worth to check it, compare, and see how it feel.

PS1: Tough also incredible, I am not sure the new pdf reader and annotation features (in beta test). It would involve exporting fonction. The key of the feature is to quickly use the right-click to generate this detailed commented bibliography. Print it, send it by mail, etc.

PS2: I saw the line about the technical complexity involved. I do not know how to do. Maybe adding a limited number of 3 to 9 columns somewhere in a database :/

Best Regards,
Théo