[Asiaplay]

yeah - understand...
So rather than overwrite the related / recommended products tbl and php... instead create another field for related categories (and make another template tbl & php for reconmended categories)... then include that in the products.tbl (so you have related products and related categories).

What I meant is code I would guess basically exists already to create this... namely copying and changing the recommended products code (and adding in recommended categories).

Cheers - Asiaplay

PS: this assumes you know php / coding to write yourself (as a standard feature or add-on module for x-cart, I have not seen this done / offered so far...)... or get someone to code for you....