A common radio code meaning "acknowledged" or "message received," frequently used in law enforcement and trucking.
It appears as a category view ID for internal image management systems (such as Phoca Gallery) used by various community websites, such as the LA7V Kongsvingergruppen amateur radio group's photo gallery. Related Concepts 473704x
If you are looking for content related to similar-sounding codes: A common radio code meaning "acknowledged" or "message
While "473704x" is not a standard FDA product code, similar alphanumerics are used to classify medical devices, such as FRG for sterilization wraps or KCT for sterilization trays. 510(k) Premarket Notification - FDA 473704x