What characters are allowed in field names?

In most cases, field (column) names may contain any character except double quote ", period ., or colon :. Underscores are displayed as spaces in the UI.

To reference a field with non-alphanumeric characters in an OPAL statement, use double quotes and prepend @..

Regex extracted columns (whether features like Extract From Text or OPAL verbs like extract_regex) are limited to alphanumeric characters (A-Z, a-z, 0-9).