Technicians often use the NAS523 code in conjunction with physical head markings to ensure correct installation: Identified by a single dimple on the head.
hosted by NASA (.gov) provides broader engineering context on selection criteria for rivets and lockbolts. nas523 pdf top
If you can specify whether you are looking for the for compliance, or a rivet identification guide for maintenance, I can help you locate the right resource. AIA/NAS - NAS523 - FASTENER CODE | GlobalSpec Technicians often use the NAS523 code in conjunction