Final answer:
If the sprinkler system is supplied from a public water main, the control valve sign may read 'City Water Supply' or 'Public Water Supply'.
Step-by-step explanation:
If the sprinkler system is supplied from a public water main, the control valve sign may read 'City Water Supply' or 'Public Water Supply'.
This indicates that the water used for the sprinkler system comes from the city's municipal water system.
These signs are typically found near the control valve or the point of connection to the water main.