Thank you Klas!
I was aware of the Search Ordering plugin, but I am interested in "seamless" sort by column implementation, such as exists in Joomla's Category List. What would you suggest as "typography" on column labels? Still on that subject, unless using hacks, there is nothing we can do to "enhance" column labels in lists displayed using Seb_Table template. Can we hope in receiving some column label options in future versions of Seblod?
In case of using Search Ordering, would that mean adding (like in the S.O. demo) something similar to: &search_ordering_city=1 (0 or 1 or 2) to the url linked to the column header?
Note: The "hack" I mentioned earlier consists in turning on JText in Seblod options, which allowed to create language overrides, and in turn resulted with COM_CCK_COLUMN_LABEL, which I was able to rewrite in language override file to contain
<a href="/...">Column Label</a>
This is not exactly an elegant solution to turn column labels into links.