Restrict Formatting and Editing Task Pane

This was called the Protect Document task pane in Word 2003.
The Restrict restrictions might be disabled if you have opened or are working on a mail merge document.

Displaying the Task Pane

In 2010, 2007, Review Tab, Protect Document > Restrict Formatting and Editing
In 2003, Tools > Protect Document

Formatting Restrictions

Limit formatting to a selection of styles -

Editing Restrictions

You can allow the following different types of editing in a document:

Tracked Changes	You can edit the document but all your changes will be tracked. Users cannot turn it off or accept or reject any changes.
Comments	You can only insert comments into this document. When you want someone to review a document but at the same time prevent changes to the original content.
Filling in Forms	You can only select and edit the form fields within the document. No selection is allowed only scrolling.
No Changes (Read only)	(Added in 2003) Password cannot be removed by the user. There is no prompt for the user to enter the password. Can only be unprotected in code.

Start Enforcement

When you have changed the relevant options press this button for the changes to be saved.
Users who know the password can remove the document protection. The document is not encrypted.

2010 dialog

2003 dialog

Restrict Permission

Information Rights Management (IRM) helps to prevent sensitive documents and e-mail messages from being forwared, edited or copied by unauthorized people.
You must have the Windows Rights Managemet client installed to use this feature.
This doesn't appear on the task pane unless you have IRM installed in 2007 and 2010 - check

Important

In 2010 and 2007 you can also display this task pane from the Developer tab, Protect Document
What is "Do Not Distribute" ?