new item types: jurisdiction, legislation, and legal

-william-

Is it possible to add three new field types: (1) jurisdiction, (2) legislation, and (3) legal, with the following fields:

@jurisdiction
title
shorttitle
journaltitle
shortjournal
pages
issue
series
volume
number
date
location

@legislation
author
title
titleaddon
number
note
journaltitle
shortjournal
volume
series
issue
pages
part
chapter
date
location
usera
addendum

@legal
title
shorttitle
journaltitle
shortjournal
issue
volume
date
pages

Thank you for your consideration,
-william-