It was a decision I made, partly because I realized they were right, and partly because I think tulips are pretty.

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      |/

um, it's a flower

“Unf” is quite widely used as a spelling of a moan, to express sexual desire or gratification. While it can be used to express non-sexual enjoyment, the sexual connotation it evokes is just unnecessary when it comes to a programming language, regardless of the original intent.

While I've never seen this use personally, UrbanDictionary very strongly corroborates this.

http://www.urbandictionary.com/define.php?term=unf

It’s worth noting that “universal noise of fucking” is a backronym—the word was originally onomatopoeic.

It is, still, but urbandictionary users like making inaccurate definitions as an attempt at "humour"

As an counter datapoint, this is the first time I have ever heard of this.

Perhaps as "umph" or "umf"? No?

No, not even slightly.

FWIW, I grew up in Scotland, then moved to England, so I'm probably from a rather different cultural background than the poster.

As a non-native speaker, I have seen "umph" before.