I visited the link you included but could not find any mention of GRAMPS. I checked the current GRAMPS documentation and it does not mention the older style of saving files. Since surname databases are now managed through the Family Manager, I am wondering how to manage my older GRAMPS surname files.
2009/11/29 . . <firstname.lastname@example.org>:
> As I stated in another post, I am just now returning to my genealogy and aI don't believe that surname files or surname directories exists in
> newer version of GRAMPS. Prior versions allowed for the saving of surname
> files into surname directories. I have many, many such directories each of
> which holds gedcoms and surname files.
the current versions of Gramps. I've never heard of them.
Looking at this post
http://www.geneamusings.com/2009_04_01_archive.html I think you might
be talking about the way gramps (before my time) used to help organise
external files. Gramps no longer does this, but of course you can do
it yourself, I have plenty of opinion and thought on the matter...