NFPA 25 Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems contains requirements for FDC signage (e.g. 4.8 and 13.7.1), for all water-based systems. Each individual standard for the specific type of system (sprinkler, standpipe, etc), there are specifications for signage.
For example, NFPA 13: 8.17.2.4.7 "Signs" specifies the signs required for an FDC servicing a sprinkler riser, including height of lettering and required legends.
NFPA 10 Standard for Portable Fire Extinguishers deals with them, among others. NFPA 1 National Fire Code tells you how many of each type of extinguisher you generally need. Other specific standards refer to specific types of hazards.
These regulations would be local laws, normally specified by the community in question. You would have to check with the specific community that you need to know about in order to find out.
Yes, plumbers working on fire suppression systems need to follow NFPA 25 as well as any other applicable NFPA and local standards (e.g., NFPA 13 for sprinkler systems, NFPA 14 for standpipes, NFPA 54 Fuel Gas Code, etc). Specialized plumbers also deal with specific standards for hazardous materials piping, according to the types of materials and the types of facilities in which they're found.
One rule for warehouse signage is to always help the customers. These warehouse signages help tourists or native people to get directions or help they need for a certain journey.
When the local code authority (NFPA) states it is needed
To regulate the voltage
No
Unless you have very crude equipment, you need regulation to prevent the destruction of equipment plugges into the system.
There is no regulation that requires them. But some sort of speed regulation is helpful, particularly if there are children in the area.
Your mom is how he did it
Can you define the term "fan room"??? We need a little more information here....
to control the pressure applied to politicans.