Use Custom Box to insert a box with user defined formatting options on the current page. Apart from the functionality provided by the Cell Box, Staff Box, Insert Object and Text Box commands, you can define and save settings like position and size, borders and margins, and wrapping behaviour for a user defined box style.
Additionally there are two predefined custom box styles: Key Box (Left Staff Side) and Cell Box (above Column), which are especially convenient for adding key signatures to a staff.
To create and add a custom box style,
choose Options, then choose Create.
To edit a custom box style,
select one of the boxes in the Box Styles list box, choose Options, then
choose Edit.
To delete a custom box style,
select one of the boxes in the Box Styles list box, choose Options, then
choose Delete.
Note: You cannot delete the predefined box styles (Default Cell Box, Default Staff Box, Default Object, Default Text Box). However, you may edit the formatting options of those styles, which affects the default appearance of the boxes inserted by the Cell Box, Staff Box, Insert Object and Text Box commands.