When you work on a document that is stored in a workspace, you can block authors from changing specific sections.
Important: The Block Authors feature is available only when your document is saved to a Microsoft SharePoint Foundation 2010 site that supports Workspaces.
Select the part of the document that you are working on.
On the Review tab, in the Protect group, click Block Authors.
The section is now marked as blocked.
Note: To remove a block, click in the blocked section, click Block Authors, and then save the file.