Using separators in column names

[iainhallam]

In the examples at https://www.dokuwiki.org/plugin:data, all the column names are single words, but there is the phrase, "Use any name you like", plus a couple of other rules. None of these mention how separators in the column name will affect the parsing.

Can a column be named date_1_dt and still be treated correctly, or should it be date-1_dt (assuming I can use hyphens in column names)? For that matter, is there a list of valid characters in the column names?