From Jargon File (4.3.1, 29 Jun 2001)
IMHO // abbrev. [from SF fandom via Usenet; abbreviation for `In My Humble Opinion'] "IMHO, mixed-case C names should be avoided, as mistyping something in the wrong case can cause hard-to-detect errors -- and they look too Pascalish anyhow." Also seen in variant forms such as IMNSHO (In My Not-So-Humble Opinion) and IMAO (In My Arrogant Opinion). It can also be InMyHonestOpinion: this is the weasel-option for when one's humbleness is later called into question. Some avoid this by writing IMO.
In practice, a request that a comment not be criticised for its factual content.
Not so. More like signalling an understanding that there may be more than one opinion on that matter that can be reasonably held, and a willingness to let these opinions stand side by side. At least that's how I understand/use it.
Not so. More normally used for a statement that is dogmantic and allows no dissension. I.e. anything but humble. IMHO, of course :)
AssumeUnirony?
IMHO this page is OffTopic anyway. The abbreviation is so widely used that any standard 'net dictionary will tell a newbie what it means.
Granted that a newbie would have a clue where to find such a dictionary. . . In my humbe opinion, AbbreviationsAreEvil
Sure, there are some people who are such newbies to the web that they don't know to Google "IMHO definition". But is it our job to cater to them? Wiki's not AOL, is it?
So now there are two ways to search for IMHO's meaning, a net dictionary and google. Are we trying to build community? I would rather that a newbie came to wiki and got "stuck" here, because this is much more the internet than the VideoMode? that is out there. Why such disrespect for newbies?
How many AOL-type internet newbies are going to be pointed to a site that is mainly concerned with design patterns, extreme programming and software development in general? And then stick around because there's such a nice definition of InMyHumbleOpinion?
WikiIsNotaDictionary, because WikiShouldDoWhatItDoesBest. Why should we try to compete with the rest of the web? The rest of the web is much bigger than us.