Typically, one card per location, but you could have one card for multiple locations.
Location Code on the Count Card specifies the actual physical location of your warehouse/business. Note: You can have a “Blank” location in NAV, but it is generally considered best practice to have at least one location set up.
On the Count Sheets themselves, you can have multiple locations for a single inventory count. Where you would use that is if you have various virtual locations within your physical location. An example of that could be if you had scrap location code within your main location, you can count that scrap location at the same time as your main stocking location. Where this can help is with the count reconciliation.
Additional filtering is also possible on the count sheet. For example, you can include filters for Bin Locations, Physical Inventory Count Period Code and so on. There is also functionality to add a Custom Filter to the count sheets. Further filtering can be done when you go to generate the count sheets.