Description

Selected altitude is one of the downlink data items transmitted in Mode S enhanced surveillance. 

Representation of selected altitude differs from one system to another but in most cases the data is shown in the track label (either as a separate field or hidden "under" another value, e.g. the cleared level but available by cycling between the two by e.g. the right mouse button). There is usually a warning (e.g. using a different colour) in case of mismatch between the cleared level and the selected altitude.