http://www.ctc.ca.gov/credentials/CREDS/adult-voc-ed.htmlAdu... Education Designated Subjects Teaching Credentials authorize the holder to teach specific academic and non-academic subjects as named on the credential in courses organized primarily for adults, and in adult education programs administered by elementary and secondary school districts. In addition, the holder may serve as a substitute in courses organized primarily for adults for not more than 30 days for any one teacher during the school year.