Click on button , pop out "Preference Editor" dialog.
In "Preference Editor", to create a new preference by clicking "Add". Preference values are determined values that represents current slice parameters setting. There are not editable;
Preference name is editable. Note: Self-defined name that is repeated or including special character like &:,;"?#%~/ is invalid.
In "Preference Editor", choose "preference", click "remove" button to delete. Only self-defined "preference" is deletable.