Since the Cataloguing module is a graphical interface, you can enter data in any sequence. Also, there may also be intermediate stages during editing when a record is temporarily invalid, for example, if you have deleted a mandatory tag or copied a non-repeatable one.

The record is validated automatically as you are entering information.

The  symbol will display next to any tag with validation errors. Hover the cursor over the symbol to display the errors, for example: 

 

All the errors in the record are displayed in a list at the top of the page, for example:

 

As the errors are corrected they will be removed automatically from the list.