Another anon here - that's just another example of how slowly the bureaucratic agencies update their manuals and guidance docs. Telegraph companies would be like Western Union, Alta California Telegraph Company, Commercial Pacific Cable Company, Desert Telegraph Company, etc. - most of which haven't been in operation in decades.
This is a lot like how examiners pay so, so much attention to "Remote Deposit Capture" customers, terrified that one day someone will unplug one of the machines in Chicago and move it down to Mexico City or somewhere, totally oblivious to the fact that any customer with a cell phone has a "remote deposit" device, already mobile, in their back pocket.