Before you certify, sign, or encrypt a PDF,
you may be prompted to select a digital ID file. To avoid being
prompted repeatedly, you can select a digital ID to use every time
you sign or certify a document.
Choose Advanced > Security Settings.
Click Digital IDs on the left, and then select the digital
ID you want to use as the default.
Click the Usage Options button , and
choose a task for which you want the digital ID as the default.
If you want to specify the digital ID as the default for two tasks,
click the Usage Options button again and select a second option.
A checkmark appears next to selected options. If you select
only the signing option, the Pen icon appears
next to the digital ID. If you select only the encryption option,
the Lock icon appears.
If you select only the certifying option, or if you select the signing
and certifying options, the Blue Ribbon icon appears.
To clear a default digital ID, repeat these steps,
and deselect the usage options you selected.