I'm wouldn't say that just because something implicitly exists makes it canon, or notable enough to merit a wiki page. I wouldn't expect that a page on MaintBox 13 that detonated the evil space probe in that season 3 episode would mean that there should then be entries for MaintBots 1 through 12.
Indeed. It ain't canon 'til it's canon.

The Omega thing is also complicated by the fact that there's and Earthforce transport 'Omega' mentioned and seen in 'By Any Means Necessary' (I think.) Needless to say it was not a destroyer. In fact I'm pretty sure it was one of these things.
On top of all that, JMS has explicitly said the first Omega was the the Achilles. End of.
Thank you Ivan Pavlov. Lucky for me that trick is only ineffective on cats.<salivates at the sound of the bell>
I actually own that particular prop. I'll take a look at it and the Crusade Bible when I get home.
Ombuds Jan
ETA: I forgot - I've got a photo of it online. http://photos.b5archivist.com/GalleryFilmstrip.aspx?gallery=212359&mid=7083446&mt=Photo&ci=008 It does only say Excalibur. I'll still check the show bible when I have a chance.

Well, if it was mentioned, it should at least have an article page. Its not like the article is taking up valuable Babylon 5 Wiki space, the wiki only has 2700 articles and even then there is a lot of doubling up on articles especially with the civilian freighters.
You do know that the value of a wiki isn't measured by the quantity of articles but by the quality, right? I seriously doubt anyone's going to want look up things on a B5 wiki that were never said to have existed. As David cgc said, if someone where to make an article of every little thing that might exist (from planets to PPGs models) based on numbering or naming schemes then it'd be a horrible, useless mess of a wiki.