The Diagram Sorter sorter, under the Tools menu provides an the fastest way to set the order of the diagrams in a model, and to delete diagrams that are orphans.

A table shows all the pages in the model, their class, whether they are unique (only one instace) and (in the Root column) the Diagram number of the first Parent symbol. These are just for guidance.

Reordering is done by selecting a sort option - this creates a new sequence of numbers into the Order column.You can also manual type numbers in.

You can preview the new order by choosing the New order option. Sorting does not actually take place until you click the 'Sort Now' button

Sort by Class

In this case diagrams are sorted by their class names

Sort by ClassSort

In this case diagrams are sorted so that they are in Class Sort order - this is defined in the Classes and Data build form, and only displayed in this form.

Hierarchy Sort

When this is selected, page ordering follows the hierarchy of the model. If a class has a KeepwithParent setting and you use Hierarchy with keeps then diagrams with the class come next after their parent diagram. Peer child diagrams are sorted according to the LoopID and then the class sort.

The 'Unique with parent' and 'Only Unique with parent' sub options determine how the class rules are interpreted.

If 'Unique with parent' is selected then a diagram is always numbered after it's parent page if is the only child of the parent page or it's class has KeepwithParent true.

If 'Only Unique with parent' is selected then a diagram is only numbered after it's parent page if is the only child of the parent page.

Mark Orphans and Delete now

Mark Orphans will set the delete column check box for all diagrams that have no parent or link jumps to them.

Delete now will delete all diagrams that have the delete column checked.

You may need to repeat this several times to remove all orphans

Referenced at Start/End

You can put Referenced diagrams at the end or start (ie starting on page 2.)

Note - You cannot change the position  of the first diagram with the diagram sort, as this would destroy and instance data.