[grok1fy]

Here's a modified version with Cyrillic, Greek and Polish (ISO-8859-2) letters, along with a few more for good measure.

ǏñҭëՐŋâťḯṏṋαłїżæŧíøṅ

[throw_away]

a truly masochistic canary would include an old ASCII control character (x00-x32) some of which I don't believe encode properly into XML as either raw bytes or literal entities and also a character off the basic multilingual plane like say linear b