Change letters in Greek Upper Letter numbering

I’m using the Greek Upper Letter numbering style for a list in Writer, but it seems to actually contain Greek numerals. The next symbol past E (Epsilon) is ΣΤ (6) rather than Z (Zeta), and after I (Iota) continues with IA (11), IB (12), IΓ (13), IΔ (14), etc.

I really do want to use the Greek upper case alphabet for my lists, not Greek numerals. Is there a way I can edit the characters used by Greek Upper Letter, modify the Greek Upper Letter library, or create custom numbering schemes for the Number: pull-down list on the Customize tab of the Bullets and Numbering dialogue?

You should surely mention the used version of LibO, your UI-language, the chosen locale, and the document language.
By the way: “Numbering” comes from “number” and should use numbers (standard representation, of course), not letters. There surely are lists now and then having more than 23 (or 26) entries.
There are languages using Latin-based alphabets “enhanced” with special characters sorted in or appended for lexical sorting…
Why cant’ we let die outdated habits with dignity?

tdf#143254 is about confusing “Greek Upper Letter” name, which should be “Greek Upper Numerals” instead.

You are welcome to file your own enhancement request about addition of a “Greek Letter” numbering scheme, like existing Roman “a, b, c, …” or Cyrillic ones.