Oh no, it’s worse.

8.5 x 11” is US Letter, or 215.9 x 279.4 mm. We also have US Legal, which as the name implies, is frequently used by legal professions. I have no idea why. It is 8.5 x 14”, or 215.9 x 355.6 mm. Finally, we have US Tabloid (I guess used for small newspapers?), which is 11 x 17”, or 279.4 x 431.8 mm.

And yes, our printers default to US Letter. The line from the movie Office Space: “PC Load Letter? WTF does that mean?” is the printer’s cryptic way of saying “Load Letter-sized paper into the Paper Cassette.”

EDIT: there are are apparently more US-specific sizes I was unaware of, which you can view and compare with others on this site: https://papersizes.io/us/