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ADOBE ACROBAT 8 STANDARD
User Guide
You can right-click/Control-click a signature field in the Signatures panel to do most signature-related tasks,
including adding, clearing, and validating signatures. In some cases, however, the signature field may become locked
after you sign it.
Expand or collapse a signature
❖
In the Signatures panel, click the plus sign (Windows) or triangle (Mac OS) next to the signature to expand it.
Click the minus sign (Windows) or the rotated triangle (Mac OS) to collapse it.
When collapsed, the signature shows only the name, date, and status.
Validate a timestamp certificate
If a signature displays the date and time, that time is the local time on the signer’s computer. However, a second date
and time may appear in the Signature Properties dialog box, indicating that the signer uses a timestamp server. To
validate a signature that contains a timestamp, you must obtain the certificate for the timestamp server and add it to
your list of trusted identities. Otherwise, the timestamp appears in the Signatures panel as unverified, and you must
validate the timestamp manually.
1
Click the Signatures button
in the navigation pane, select the signature, and choose Validate Signature from
the Options menu.
2
Click the Signature Properties button in the Signature Validation Status dialog box.
3
In the Signature Properties dialog box, click the Date/Time tab to view the timestamp authority, and then click
the Show Certificate button. (This button appears in the Date/Time tab only if the signer used a timestamp server.)
4
In the Certificate Viewer, click the Trust tab to determine if the timestamp certificate is trusted. If it isn’t trusted,
click Add To Trusted Identities. If a certificate for the timestamp server isn’t listed, request one from the signer.
See also
“Sharing and managing certificates” on page 203
View previous versions of a signed document
Each time a document is signed, a signed version of the PDF is saved with the PDF. Each version is saved as append
only so that it cannot be modified. All signatures and their corresponding versions can be accessed from the Signa
tures panel.
1
In the Signatures panel, select the signature, and choose View Signed Version from the Option menu.
The previous version opens in a new PDF, with the version information and the name of the signer in the title bar.
2
To return to the original document, choose the document name from the Window menu.
Compare versions of a signed document
After a document is signed, you can display a list of the changes made to the document after the last version.
1
In the Signatures panel, select the signature.
2
Choose Compare Signed Version To Current Version from the Option menu.
3
When you’re done, close the temporary document.