What must be indicated on the tag alongside static and flow pressures?

When tagging sprinkler systems to provide crucial information for maintenance and safety, showing the drain test results alongside static and flow pressures is critical. This information indicates how well the system can drain water, which is essential for ensuring the system is functioning effectively and can manage pressures appropriately.

Including this result ensures that anyone inspecting the system can evaluate its performance and check for any potential issues that might affect the sprinkler system's reliability during operation. Drain tests, in particular, help confirm that the system can adequately clear standing water, which can impact performance and reliability.

The other choices, while important for overall system management, do not directly relate to the immediate assessment of pressures within the system. The inspection date helps track maintenance timelines, the maintenance schedule guides regular upkeep, and service history offers insights into repairs and modifications made. However, it is the drain test results that provide critical operational insight when paired with static and flow pressure measurements.