Restrict printing or changes to a document
1.		With the PDF document open, choose Document > Security > Restrict Opening and Editing.
2.		In the Password Security dialog box, select which version of Acrobat is required to read the document.
3.		Select the check box under Permissions, and then type a Permissions password. This password is not required to open the document, but only to change the security settings. It must be different than the Document Open password.
4.		Specify which printing and editing changes are restricted or allowed, and then click OK.
5.		Confirm the Permissions password, and then click OK.
Note:  For heightened security, specify a Document Open Password.
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Add a document password
Security Topics
Adding passwords and setting security options in complete Help