Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.
The other day I was trying to execute a search against content server in some JSP's (Java Server Page) and I wanted to perform a multi column sort, similar to how the old Multi-Sort component used to work. The content server in question was configured for DATABASE.FULLTEXT. Turns out, this is simple to perform. When you form your URL or binder (Local Data?) you need a variable named SortSpec and it should start with "order by" and follow the basic rules of a database query.
Example:
SortSpec=order by dDocType asc, dDocName desc
Another example:
http://yourserver/instance/idcplg?<original query>&SortSpec=order%20by%20dDocType%20desc,%20dDocName%20asc