Caution regarding the csv file format -- The csv file format does not retain data formatting.
This can cause problems if, for example, you have usernames that begin with leading zeros. When reopening a csv file for further edit, Excel will assume your numeric data does not require the leading zeros and it eliminates them. Also see Quick Topic - Helpful Excel Tips for Importing Data.
Similarly, certain data that may have been intended to be formatted as a date (e.g. 07/12), may be interpreted as a numeric value. For this reason, you may want to always work with the native .xls spreadsheet format (which retains proper formatting), and once you are ready to import the file, do a "save as" into the .csv format.
Double Quotes -- Excel will add the double quotes around fields for you automatically for any fields that contain commas.
Manually adding double quotes within Excel would result in multiple sets of double quotes in the resulting .csv file and thus cause an error (should you attempt to import that resulting file).
If using a special tag such as !RENAME!,old_value,new_value -- and either the old or new value contains a comma within the data string, you will need to enclose that portion of the string within its own set of double quotes, for example:
!RENAME!,old_value,"new,value"
Do note that when saving such a value to a .cvs format, Excel will translate the above into the following (as it detects the commas within a cell and encloses the entire string within a pair of double quotes, and also detects the quotes you have entered -- and enclosed those in another set of double quotes. This is standard Microsoft csv file quoting behavior). Just note that if you were attempting to programmatically create this file (or manually create it using a text editor), you would need to follow these quoting rules. When viewed using a standard text editor, the eventual field would look as follows:
"!RENAME!,old_value,""new,value"""
Header Row Ignored -- When creating a comma delimited file using Excel, the saved ascii text file will contain a header row. This row will be ignored by the import process and will not create any import warnings. The import process will ignore the header row (i.e. the first row is considered a 'header' so long as the very first character is an *), as well as any other rows that begin with ** (two asterisks) - which represents a commented out entry.
Saving Excel Templates -- Depending on the browser you use, you may need to right click the template link and use the "Save Target As" feature to save a copy of the template.