Adobe Acrobat 8 3D - Manual (Page 254)

247 ADOBE ACROBAT 3D VERSION 8
User Guide
Recipients can extract and save the encrypted documents. Once saved, the documents are no longer encrypted.
See also
“Create secure attachments” on page 268
Opening restricted documents
Open secured PDFs
If you receive a PDF that is protected by security features, you may need a password to open the document. Some
protected documents have restrictions that prevent you from printing, editing, or copying content in the document.
If a document has restricted features, any tools and menu items related to those features are dimmed.
❖ If a document is restricted or has a special status, the Security Settings button or the Signatures button
appear to the left of the document window. Click the button to discover the protection settings and determine which
features are restricted.
If you have trouble opening a PDF, or if you’re restricted from using certain features, contact the author of the PDF.
Restrict URLs and attachments in PDFs
Acrobat warns you any time you try to open a URL (web link) or a file attachment that uses a disallowed file type.
URLs and disallowed file types (for example, EXE) are potentially dangerous because they can transfer or run
programs, macros, or viruses that can damage your computer.
You can allow Acrobat to contact specific websites by adding those URLs to your list of allowed websites in the Trust
Manager preferences. Remove any URLs you no longer want to visit. To open file attachments in Acrobat, you must
respond to a prompt by indicating that you always allow files of that type. The attachment’s file type is then added to
a list stored in the registry. If you want to restrict a file type that you permitted in the past, you can reset this list to
its default settings in the Trust Manager preferences.
Trust Manager preferences
To open the Trust Manager preferences, choose Edit > Preferences (Windows) or Acrobat > Preferences (Mac OS),
and select Trust Manager on the left.
Allow Opening Of Non-PDF File Attachments With External Applications When selected, allows file attachments to
start external applications when you open the files. You must have the external applications to open the files.
Restore Default List Of Allowed And Disallowed File Attachment Types Removes saved settings you chose for
opening attachments. For example, if you chose to always open TMP attachments when prompted, TMP appears on
the list of allowed file attachment types. By clicking Restore, you remove TMP from the list.
Change Settings When clicked, lets you specify the default behavior for accessing the Internet from PDFs. To
restrict access to only the URLs you specify, select Let Me Specify A List Of Allowed And Blocked Web Sites (the
default). To allow access to all URLs, select Allow All Web Sites. To restrict access with all URLs in PDFs, select Block
All Web Sites.
To specify a list of allowed and blocked websites, type each URL in the text box, and click Allow or Block. Then
specify the default behavior for Acrobat for websites that aren’t in the list.