If you use the metadata plug-in (for embedding sort information in the class attribute,) then the tablesorter has a built-in parser for using that value.

This gives you the same flexibility as using the comments, but doesn’t require additional plug-ins. I use this to sort dates:

Date

#getRecords.date#

I’m using javaCast() to cast the date into a numeric value. This allows me to display the date however I want, but the sorter will still sort the date correctly.