[bookofjoe]

FWIW the only place I EVER see the phrase "citation needed" is on HN. That's not a good or a bad thing: it's simply an observation.

[mrec]

Pretty sure it originated with the Wikipedia annotation. See e.g. https://xkcd.com/285/ from 2007.

[analog31]

With apologies to the above post if I'm wrong, I've seen it as a polite way of saying, "bullshit."

[mapontosevenths]

> I've seen it as a polite way of saying, "bullshit."

Only if they can't provide a reliable citation.