There are 3 or 4 blue book citation formats available. What are the differences? Are the more recent (2013) versions improved over the 2009 (Dev) version?
The Bluebook styles in the official Zotero style repository haven't had much attention for the past couple of years. That's not due to neglect; full support for the Bluebook style is difficult at present, given some (temporary) limitations in Zotero. Depending on your needs, more complete support for legal styles is available in an unofficial variant, Multilingual Zotero (MLZ). Be sure to read the notes below and on the site before installing.
Unless you are making heavy use of primary resources, I would recommend sticking with official Zotero until you have your workflow set up and are comfortable with the system. You can convert to MLZ at any time. You can move back to official Zotero after, but it is a little awkward. (MLZ is my own project, not supported by the core team, so whether to use it is a judgment call -- there are trade-offs, the choice depends on your priorities.)
Full support for legal citations will be coming to official Zotero in due course, but there are currently some things that can't be done in the standard styles. A partial list ...
Jurisdiction-specific cite forms
Official Zotero does not yet have a jurisdiction field, so a style can cover only one jurisdiction. In Bluebook, cites to foreign jurisdictions (Canada, the UK) will be formatted in the US style.
Vendor-neutral case cites
About a dozen jurisdictions in the US have adopted vendor-neutral citation forms. Support for these special forms is not possible without the jurisdiction field mentioned above.
Statute pinpoint back-references
For research purposes, it is most convenient to store individual statutory provisions as separate Zotero items; but in that case, when citations are inserted into a document, references to separate provisions of the US Code (say) will not trigger id. back-references as expected.
Treaties
Official Zotero does not have a Treaty type. There are some special requirements there, particularly with respect to dates, so producing cites to treaties is a bit difficult.
Just to add and maybe lend additional support: I do most of the style development for the official CSL (and thus Zotero) development and the principal reason I'm not doing much in terms of law styles (unless someone specifically commissions one, as has been the case for AGLC and OSCOLA) is that I think people who are serious about legal citations should just be using Frank's MLZ and it's a waste of my time to hack something for CSL/Zotero that MLZ can do much better.
Is MLZ used in connection with a Zotero collection? Or is MLZ a separate database entirely? I went to the MLZ website and did not see anywhere to clarify how to use an MLZ bibliography manager for citation style. Can anyone clarify? Thanks, SherryE./Atlanta
Note that MLZ does not exist under that name any more nor is the above-linked website relevant. The project is now called juris-m and lives here: https://juris-m.github.io/
It is a separate app that can read in an existing Zotero database and can sync through the Zotero server (including with Zotero installed on a different computer) but cannot easily be used in parallel on the same computer with Zotero (it's not impossible, just not easy).
Upgrade Storage
Unless you are making heavy use of primary resources, I would recommend sticking with official Zotero until you have your workflow set up and are comfortable with the system. You can convert to MLZ at any time. You can move back to official Zotero after, but it is a little awkward. (MLZ is my own project, not supported by the core team, so whether to use it is a judgment call -- there are trade-offs, the choice depends on your priorities.)
Full support for legal citations will be coming to official Zotero in due course, but there are currently some things that can't be done in the standard styles. A partial list ...
It is a separate app that can read in an existing Zotero database and can sync through the Zotero server (including with Zotero installed on a different computer) but cannot easily be used in parallel on the same computer with Zotero (it's not impossible, just not easy).