One of the tablesorter clones [1] allows for a very useful override of sorting rules by defining a function, as illustrated at [2] and documented at [3].

This seems really useful for all kinds of special cases, such as sorting with differ keys on descending order than on ascending orders and would perhaps make T47161 easier to implement (as the different parsers could be offered as functions that can be implemented independently)

[1] https://github.com/Mottie/tablesorter
[2] http://stackoverflow.com/questions/27850608/jquery-tablesorter-determining-sort-order-for-column/27865429#27865429
[3] https://mottie.github.io/tablesorter/docs/example-option-custom-sort.html