Setting Interactivity as Mandatory ensures that your visitors participate or complete a certain aspect of your document - they won't be able to progress to the next page until the Interactivity has been selected or completed.
Example
HR have sent out a job offer to Jane and require her to accept the T&Cs of the role. The job offer pack contains a More Information pop-up box positioned over a button that says 'Accept T&C's' - setting the More Information module as mandatory ensures that Jane has accepted the T&C's and can progress with her accepting the job. Simple!
How to set a module as Mandatory
Navigate to a Document.
Select ‘Interactivity’ for the version of the Document.
Click on the piece of Interactivity that you would like to set as Mandatory.
Select the Mandatory icon from the flyout menu.
💡 The Mandatory icon looks like this --> 
Tick the ‘Mandatory’ checkbox to set the module as mandatory.
Select the 'Edit Message' button to enter a mandatory message of your choice.
💡A mandatory message is a short piece of text that displays in a pop-up box if the visitor attempts to turn the page before completing mandatory Interactivity.
And that's it! The piece of Interactivity is now mandatory, and the visitor cannot turn the page unless they have engaged with it.
Assessment modules and Mandatory
Assessment modules work slightly differently, as they have various ‘Results’, which in turn, enable more Mandatory options. The module itself can still be set as Mandatory to ensure it is completed, however a particular 'Result' can also be set as Mandatory, meaning the visitor has to achieve it to continue.
💡 A 'Result' is a message that displays to a visitor based on the score achieved after completing the assessment. Find out more about Assessment modules.
Click on the piece of Interactivity that you would like to set as Mandatory.
Select the Mandatory icon from the flyout menu.
Each possible Result for the Assessment will display - simply tick the checkbox for the Result you want to make Mandatory.
Example
Jane is completing some Health & Safety Training in her new role. When she reaches the end of each section she's presented with a quiz. The 'Pass' result has been set as Mandatory, meaning she has to pass the quiz before she can continue to the next section.