Standard signage in a building refers to the three types you'll need which are, primary, secondary and tertiary signs. They are essential to identify which room is which and often play a crucial part in successfully gaining occupancy. They are typically found mounted directly on the door of the room they identify or mounted on the wall on the doors latch side.
A primary sign is used when the public will directly see the sign itself. It is also used to identify things like amenities such as washrooms, pools, spas, gyms, or lounges. These are usually the most expensive sign in the bunch as they are the best looking of the three.
A secondary sign is also used as an identifier where the public will see it. Though they are visible, they are more commonly used with things like garbage disposals, electrical closets, storage closets, and telecommunication rooms. These signs will often match the same design as the primary but tend to be smaller in size which results in a lower cost.
Tertiary signs are meant to be use where nobody but building staff will see them. They are used just the same as secondary signs and are meant to identify rooms like mechanical rooms, pump rooms, or elevator rooms. They are typically made of lower quality materials and in turn will come at a lower cost.