But it hasn't always been easy to find documentation about it, thanks to a combination I think of "simplifying" everything and Google not delivering correct results since somewhere around 2010.
Thankfully now there is Kagi that actually makes a bug report if you provide them with an example that doesn't work.
I think I've been using that shortcut for as long as I can remember. In web development circles it's certainly common knowledge, as you always end up in a situation or two where you need to reload without cache, but you don't want to clear the entire browser's cache.
I'm pretty sure I remember using it earlier than that but can't be 100%.
[1] https://bugzilla.mozilla.org/show_bug.cgi?id=46845#c7
[2] http://www.bu.edu/uis_web3270/en/doc/troubleshoot/pd_ck_down...