The phrase "are requested not to" is correct and usable in written English.
It can be used in formal contexts to politely ask someone to refrain from doing something.
Example: "All employees are requested not to use personal devices during work hours."
Alternatives: "are asked not to" or "are advised against".
Foil savers are requested not to wad their foil up into a lump.
Patrons are requested not to park in the equally limited lot of the adjoining shops; try the side street north of the strip.
The New Yorker, August 27 , 1927P. 9 Couple at tennis matches: Referee announced that spectators are requested not to applaud during rallies.
The users are requested not to pass the data on to a third party and asked that they acknowledge Rothamsted Research as the source of the data in any publications.
By Harold Buck, Geoffrey T. Hellman, and Emil Zubryn The New Yorker, May 9 , 1953P. 24 Behavioristic Intelligence: At the Salon Mexico, a dime- a-dance hall in Mexico City, a sign says, "The senores are requested not to throw cigarette butts on the floor, so that the senoritas will not burn their feet".
A Serio-Comic Ballad, During the singing of which, people are requested not to laugh.
Chief executive Phil Clapp said: "Customers will be requested not to wear these into cinema auditoriums, whether the film is playing or not".
It is not fair on the many thousands of hardworking members of Ukip to have one person take attention away from their efforts and successes by promoting their own controversial views despite being requested not to do so".
Weapons manufacturers have been requested not to display cluster bombs at next month's military equipment exhibition in the London Docklands because they are considered "inappropriate" for the UK market.
The D st index, which measures the activity of the magnetic field generated by the ring current, is requested not to exceed 5 nT in absolute value.
To prevent the mis-classification of migraine phases or the distracted effect on EEG, patients were requested not to take analgesics within 2 days before EEG recording, nor take any psychotropic drugs within 4 weeks before the EEG study.
