Which data point is mandatory related to a Purchase order?

[pastrana]

When receiving software related to a purchase order in ServiceNow, which data point is mandatory? Serial Number / Assigned To / Cost / License key / Asset Tag.

I believe the right answer is Serial Number based on my current PDI instance, others mention is the Asset Tag. Can somebody please clarify this?

Is not documented by ServiceNow and was a question in the CIS-SAM exam.

[Alok1917]

Yes it is documented - snippet below 

[p_tishberg]

Purchase orders, either in advance shipping notification list of records (ASN) or upon delivery will contain a Serial Number for every asset received.  Asset Tag, UNLESS previously discussed w/Manufacturer or Reseller, won't use Asset Tag. 

By default, the Asset Tag is unique ONLY to your organization.  2 organizations may have an Asset Tag for a laptop as "LAP0011" but no two organizations will ever have the same laptop manufacturer, make &  model, and the same serial number.  So from the start, the Serial Number is unique as the earliest primary indexable field. 

Many organizations use barcodes or logically through software counters, add an Asset Tag as part of receiving assets at the point of delivery (warehouse, stockroom, receiving dock,...)