Under Item Model group if registration is compulsory and attached to Item then before making Purchase Order based Product receipt Item registration is required for the purpose of tracking dimension and batches. Example: I personally faced one issue where the Project controller requires the item to be tracked with bar code to all the electric tools and trying push it as Asset whereas on other hand finance rejects this as asset item, the solution was to have new item model group with Tracking dimension enabled.
How it work?
The PO, return orders or transfer orders items attached with Tracking dimension is preferred way of tracking, when item is arrived we can simply register items as registered with bar code or serial no generated then only receipt is done to post inventory Journal.
Use direct lines from receipt or in bulk best way is to use Item arrival overview available in both AX & D365
Note: Item registration do not post any physical update