Cues are passages of music shown in instrumental parts that are played by a different player, usually to help orientate players before entries or solos following a significant passage of rests.
Cues can also be used to assist with coordination or tuning between players, or to indicate material that the player might be asked to double.
Note
In Dorico Elements, you cannot input or edit cues. However, cues are shown if you import or open a project that contains them.