This dialog is shown when pasting multiple measures into a selection of measures less than that being pasted.

Paste selection only

Pastes only what will fit into the measures that are selected.

Overwrite to paste all measures

Pastes everything replacing the contents of the measures selected and measures there after.

Insert all measures into the selection

Replaces the measures selected, and makes room for the rest of the measures.

Cancel

No pasting action is performed, allows you to make a new selection.