One of the most important parts of a sprinkler system is the sprinkler head itself. Without a properly functioning sprinkler head, the system will certainly not detect and control or extinguish a fire. All sprinkler standards include requirements and/or advice on how to carry out maintenance in order to keep the installation in a state where it will function when needed.
Adding a production date on the head is actually quite common since the first sprinkler heads appeared on the market. Adding a date is also mentioned as a requirement in modern product standards like FM class 20003, ‘the following shall be displayed on a non-operating part of the sprinkler: Year of manufacture…’