Modern Greek alphabet identities derived from Unicode 17.0.0 UnicodeData.txt.
Source: https://www.unicode.org/Public/17.0.0/ucd/UnicodeData.txt
Unicode data is distributed under Unicode License v3. The unmodified license is retained in unicode-license.txt.
The conventional 24-letter order is explicit. Unicode LAMDA is displayed as lambda; both name spellings are accepted. U+03C2 is the final-sigma form of sigma, not an additional letter.
Quiz wording and interface are original to GizmoBench.

Run node public/greek-alphabet-practice/build-map.mjs to reproduce alphabet-v17.json from the pinned local source. Pinned source sizes and hashes are checked before any output is written.