Dynamics 365 FO / AX - thoughts on application development and customizations

Ever wonder what the AliasFor property on a table field is used for ? It is actually a pretty nifty little feature of the AX runtime. I was tasked with making a solution for the following problem: * Introduce a new field on the item table that can hold the EAN number of the item. * Enable the user to be able to type in either the item id OR the EAN number when searching for an item to put on e.g. a sales order line. * Make sure that the EAN number is shown in the look up lists This actually quite easy to do. First I created the EAN number field on the InventTable using a new extended datatype created for that purpose. Then I created a new index on the InventTable containing the new field. This of course makes for searching for EAN numbers effeciently, but it also makes the EAN number field appear in the lookup list. The final thing to do was to set the AliasFor property of the new EAN Number field to be an alias for ItemId, by assigning the value ItemId to the property. Now "magic...