When recording, copying or moving a scene, if the destination location already has a scene recorded in it, you will be prompted with record options of Insert, Merge or Replace:
Insert: creates a new destination scene. The new scene will be assigned a free location just before the one chosen, using a point number if necessary.
Merge: Incorporates the new information into the destination scene. If the same fixture parameters are in both scenes, the new values will replace the old.
Replace: Overwrites the scene information in that destination.
If you are copying a scene, all three options are available. If you are moving a scene, only the Insert option is available.
If you know that you are about to record, copy or move a scene to an existing destination, you can pre-select Insert, Merge or Replace from the Record Options Toolbar. This appears after you press the Record, Copy or Move keys.