26.1.

Primary tabs

Secondary tabs

Warning: Opening delimited text files with spreadsheet applications may expose you to formula injection or other security vulnerabilities. When the submissions contain data from untrusted users and the downloaded file will be used with spreadsheets, use Microsoft Excel format.

This is the delimiter used in the CSV/TSV file when downloading Webform results. Using tabs in the export is the most reliable method for preserving non-latin characters. You may want to change this to another character depending on the program with which you anticipate importing results.
Choose whether to show the label or form key in each column header.