Elevator pushbutton for external control
Elevators are typically controlled by passengers through the control panel composed of up and down call buttons at every stop. When a passenger presses on the up or down elevator pushbutton, it will call the elevator serving traffic in the area to answer the call in the floor where the call from unless there are no other calls beyond that floor. Typically, the elevator will delayed if it has to respond to other calls from passengers wishing to travel in the same direction. This is a scenario common during peak hours when many passengers are waiting to board the car to different destinations.
Elevator pushbutton for internal control
Inside the elevator cab, there are more call buttons to push designed for easy passenger navigation. The call buttons are numbered according to floors so that if the passenger pushes on the call button with a number 5, the elevator will bring the passenger to the fifth floor. In other parts of the world, aside from the elevator pushbutton, there is a Braille system for those who are visually impaired. This is a requirement under the Americans with Disabilities Act. In fact, even if the elevator controls have been replaced with the dispatch system, the Braille numbers are still required in compliance with the law.
Elevator pushbutton and labels
In English-speaking countries, the elevator pushbutton can be labeled according to its function. For example L can stand for lobby while P may either be pool or parking; R may mean roof, PH for penthouse or G for garage. This is very common in high-rise modern buildings to make it easier for the passengers to figure out their destination. However, there are instances when it is better to seek for assistance since G may not mean garage but ground floor which is on street level. In some buildings where there are levels below ground, you will find elevator pushbuttons with labels like UG for upper ground, LL for lower ground, B for basement or a C for the cellar.
Different schemes can be used for elevators so that the labels in the elevator pushbutton become a source of confusion particularly for first-time passengers. However, there is no law in existence that has standardized the labels on the call buttons. A letter or number may actually mean a different thing from what you are accustomed to in your building, though certainly it wouldn’t hurt to ask.