Well there is no active account with name of TabsInTitleNOTMini_2 on forums.mozillazine.org as otherwise you would not have been able to use it while as a Guest poster. There is no inactive account with name of TabsInTitleNOTMini_2 either.

No account with that name at sumo either [url]https://support.mozilla.org/en-US/user/TabsInTitleNOTMini_2[/url]

I don't think any accounts are intentionally deleted here as that is a generic FAQ sentence. Many years ago there was a database issue in which some people lost their accounts.

We do however deactivate accounts that were used for spamming.

I don't see any such user ID around that date. Are you sure that you were registering on these forums and not this one -- https://support.mozilla.org/en-US/products/firefox

[quote]I understand removing inactive / 'posts-thrice-per-decade' usernames from the database; however the(ir) post(s) should be kept:[/quote]
Why, if it was only one and (apparently) received no replies?

http://forums.mozillazine.org/faq.php#f0r6 :
"[...] [i]many boards periodically remove users who have not posted for a
long time to reduce the size of the database.[/i]"

Does this ALSO remove their posts !??.. I registered 015 Dec 28 with user name
"TabsInTitleNOTMini" and posted a message about tabs _not_ being in the title
bar when the window is not _maximized_ (made a typo when creating the user
name). However a google search "tabs title bar not maximized site:mozillazine.org"
around that epoch does not yield _my_ post (I see there have been other posts
on this subject since :-), i will check them!).

I understand removing inactive / 'posts-thrice-per-decade' usernames from the
database; however the(ir) post(s) should be kept: I have seen this being done
by changing the poster to 'Anon' before deleting the user profile.

TabsInTitleNOTMini_2