> First on the standard list of metasyntactic variables used in
syntax examples (bar, baz, qux, quux, corge, grault, garply,
waldo, fred, plugh, xyzzy, thud)
I've seen foo, bar, baz, qu+x, plugh and xyxxy actually in use, not the others.
I've not used "qux" or followed the convention of adding more u's. From me it's been just foo, bar, baz, quux and then some Monty Python inspired ones: spam, ni, ecky, ptong.
Although eventually I learned enough about how to name things that I don't feel the temptation any more. I'll gladly pay that bit of joylessness to understand myself months later.