By default my products are being displayed with the sort order of product ID, descending, as far as I can see, a sort order as useless as it is nonsensical. I want to display products for a given category in an arbitrary order. So I created an attribute "display order", validated as an integer and added that attribute to my products. I set the values to 100, 200, 300, etc. according to the order in which I want the products displayed. I set the value of "Used for sorting in product listing" to Yes.
For the scope of the product sub-category concerned, but also for the root category, I select that attribute for both "Available product listing sort by" and "Default product listing sort by". I clean the cache on the server and clear the browser cache.
These settings are ignored and the products are still listed in the same, useless way. So what is the problem? Does the theme not support this method? Is there a bug? Have I missed something in the configuration? Do I need to add custom code?