Protect Document is an option provided by Visio to protect users from changing document attributes like Style, Shapes, Preview, Backgrounds and Master shapes. The Protect Document option is available by clicking on the document name in the Diagram Explorer window.

The Diagram Explorer option is located under the Developer menu. To be able to use the Developer menu administrator’s rights in Visio is necessary.

If you do not have administrator’s rights the options, for example Delete Page, will be disabled.