A circular letter is a letter to order or to inform a set of persons of an internal group about a matter. This letter is sent by a Superior to his subordinates.
(Place and date)
TO THE PERSONNEL OF THE DEPARTMENT OF VIGILANCE
In order to adopt the new measures to preserve the internal safety of this company, I report you that from this date, the members of this Department will have to check that all the employees without exception carry his identification as they get in and out the building, as well as during his permanency inside the offices and other areas of work. Also it is an obligation of all the people who enter the building, to show the content of his handbags, portfolioes, suitcases, and in the glove compartments and interiors of their vehicles.
Any irregularity that commits an outrage against the safety procedure, must be reported immediately to the Management of Protection and Security.