The Certificate of Appreciation is available on-line to all members in the U.S. Coast Guard Auxiliary Certificate Database at http://certs.cgaux.org/
The certificate is designed for the local level leadership to use as needed.  Although the certificate is not password protected, the site requires your Auxiliary ID and "eDirectory" password for access.

Your flotilla's Materials Officer (FSO-MA) may obtain the ANSC 6020, Certificate of Appreciation, or ANSC 6021, Certificate of Appointment, from the Auxiliary National Supply Center (ANSC).  The catalog, itself, is listed under "Manuals & Publications" on the Chief Director's Web site.

[Updated 4/2/2014]