This file, which is part of every Cumulus software distribution (1, 2 and MX) and stored in the top level folder for Cumulus, contains the standard names for each field in the Extra Sensor Files.
You can vary the names used for your implementation by editing Strings.ini.
The separating character between field names is "|", so you can open this in a CSV editor, or in spreadsheet software like Libre Office Calc, if you tell the software to use that as column separator. Note that the actual log files do not contain this header, so if for the purposes of editing a file outside Cumulus, you insert this line to identify the columns of numbers, you must delete this line before returning the file to Cumulus.
Content of this file varies depending on which build you are running, so an example has not been included here.