miller/docs6/docs/internationalization.md

Internationalization

Miller handles ASCII and UTF-8 strings. (I have no plans to support UTF-16 or ISO-8859-1.)

Support for internationalization includes:

• Tabular output formats such pprint and xtab (see File Formats) are aligned correctly.
• The strlen function correctly counts UTF-8 codepoints rather than bytes.
• The toupper, tolower, and capitalize DSL functions operate within the capabilities of the Go libraries.

Please file an issue at https://github.com/johnkerl/miller if you encounter bugs related to internationalization (or anything else for that matter).