[ic] Foundation Store - How to sort category results

[Gilbert Meyer-Gauen]

Hello IC Experts,

I have a simple problem with the "Foundation" store that I would like 
to use to build a shopping cart.  I am relatively new to Interchange, 
so please bear with me if this question is too trivial for some.

I have a category list on the left side of the shopping cart that 
displays perfectly the different categories of my product catalog. 
The category links put out the correct item list once you click on 
them, so that works as well.  However, I would like to have the 
resulting pages sorted by the sku when you click on the category 
links.

I know that I have to include tf=sku somewhere, but I simply can't 
figure out where.  I tried it in category_vertical, but that is only 
for the category display on the page.

Any help is highly appreciated.

Thanks in advance, Gil