So basically, this is a look at what "fishbowl" wikis there are. Some are private and little known, and in general these wikis are used in conjunction with the mailing lists.
The canonical WMF owned domains are hard coded into the Google Chrome web-browser, currently, they are:
wikipedia.org
wikimedia.org
wiktionary.org
wikiquote.org
wikibooks.org
wikisource.org
wikinews.org
wikiversity.org
wikidata.org
wikivoyage.org
wikimediafoundation.org
mediawiki.org
wmfusercontent.org
w.wiki
There are other domains owned by the WMF, but they are not relevant here because they are generally only used as redirects or for tools, for example tools.wmflabs.org. Note that en.wikipedia.org is a subdomain of wikipedia.org, it is not a separate domain in itself, all the different languages are handled by subdomains in this way. Therefore all WMF main wiki's are listed in the STS preload list as a few domains, although there are many hundreds of subdomains.
This itself is not very relevant, what is important is looking at the subdomains for wikimedia.org. These are generally not SUL enabled wikis, and are either less well known or access restricted.
wikitech.wikimedia.org
An internal tech wiki, open access and mainly used by devs for wikimedia specific docs and configuration notes. (General tech notes not wikimedia specific go on mediawiki.org instead).
meta.wikimedia.org
Everyone knows about meta, it's a wiki for discussing other wiki's, and for doing coordination and documentation as well as planning and analysis of stuff.
Various pointless wikis
A number of Wikis such as; ten.wikipedia.org, quality.wikimedia.org, usability.wikimedia.org, strategy.wikimedia.org, outreach.wikimedia.org were all made for various high level processes and eventually discontinued in favour of meta-wiki.
wikimania2018.wikimedia.org etc
This is a set of fourteen wikis for the wikimania event, starting in 2005 one has been made each year. Open access but edit locked once the event year is over.
wikimaniateamwiki
Initially I thought this was wikimania.wikimedia.org, but later realised it was the restricted access wikimaniateam.wikimedia.org.
nyc.wikimedia.org etc
Seventeen wikis specifically for Wikimedia chapters, the British chapter breaks the trend with wikimedia.org.uk, and Norway also has noboard-chapters.wikimedia.org. Four of the chapter sites seem to be in some way locked with others restricted.
foundation.wikimedia.org
Used to be a wiki for the Wikimedia Foundation, now somewhat superseded by wikimediafoundation.org which is hosted on wordpress (widely considered to be a massive sellout) and completely closed.
advisorswiki
A closed private wiki historically used by the Advisory Board (meta-page) in conjunction with their mailing list.
internal.wikimedia.org
Used historically by the Wikimedia Foundation board and staff members and other trusted people, fell out of use by 2015, and was closed in October 2018.
chairwiki
Almost never used, and now being closed, was originally for the Wikimedia board.
arbcom-enwiki
A private wiki for the English Wikipedia arbitration committee. It is one of a set of arbcom wikis for the different language projects, and has changed domain name before, see T33335 and T102814 and T102826. Other arbcom wikis include; arbcom-cswiki, arbcom-dewiki, arbcom-fiwiki and arbcom-nlwiki.
dumps.wikimedia.org
This wiki contains backup dumps of all Wikimedia sites for interested people to download.
auditcom.wikimedia.org
Used mainly prior to 2008 by the Wikimedia Foundation Audit Committee
checkuserwiki
This wiki is used to indefinitely store data on hundreds of sockpuppets and LTA's for years longer than the CU tool maintains logs. It is a generally accepted fact that this wiki holds detailed SPI type logs on many users, and charts to assist in finding socks, the general consensus is that most LTA pages that were deleted per WP:DENY from Wikipedia were kept here and expanded.
stewardwiki
Everything you ever wanted to know about the stewards... behind a firewall.
OTRS-wiki
Part of the OTRS system, basically used by OTRS volunteers to coordinate with the OTRS ticket system, email queues, and freenode IRC channels (of which there is the public OTRS channel, the private channel, and several invite only interview rooms.)
zerowiki
The rather crappy "Wikipedia Zero" project.
loginwiki
This wiki governs logins on all SUL wiki infrastructure, stewards can run a CU check on this wiki to check user details globally. It connects a live feed to an irc channel (#internal on irc.wikimedia.org:6667) for bots to use login data.
And many many more, such as:
grantswiki
Closed in 2006 in favour of some other process, this was a private wiki for grants administration.
boardwiki
Used by the Wikimedia Foundation Board of Trustees for internal documentation.
boardgovcomwiki
Probably not used, but yet another wiki for the Wikimedia Foundation Board of Trustees
chapcomwiki
A private work space for the Affiliations Committee.
And a whole bunch of private wiki sites that nobody talks about
collabwiki
ecwikimedia
execwiki
electcomwiki
fdcwiki
id_internalwikimedia
movementroleswiki
ilwikimedia
legalteamwiki
officewiki
ombudsmenwiki
iegcomwiki
projectcomwiki
wg_enwiki
transitionteamwiki
techconductwiki
searchcomwiki
spcomwiki
Which I cannot be asked to figure out the urls for right now.