So to reply to my own question, a minimal standard would be the first four code blocks, plus Greek, math operators, and box drawing symbols. Anonymous Pro and

So to reply to my own question, a minimal standard would be the first four code blocks, plus Greek, math operators, and box drawing symbols. Anonymous Pro and Andale Mono reach this standard, Inconsolata doesn't. A higher standard would be Menlo and Courier New, both having all those plus the Greek Extended (with accents), Cyrillic, Hebrew and Arabic sets, and a mess of other symbols. Deja Vu Sans Mono is missing the Hebrew, at least the version I have, but adds a bunch of dingbats and miscellaneous symbols. Everson Mono (not mentioned in the subject article and not a great programming font) has even more, all the odd-ball language support like Lao and Gothic. Edit after checking the others mentioned: Only Menlo, Courier New, and Liberation Mono have Hebrew, a bit of a surprise given how much software is done in Israel. Those three have the largest complements of glyphs, and Liberation Mono is open and free.