de in output. Takes the form of a comma separated list of purposes, a colon, and a comma separated list of levels. The default is to include all certificates trusted to issue SSL Server certificates (SERVER_AUTH:TRUSTED_DELEGATOR). 
<p class="level1">(Added in version 1.21, Perl only) 
<p class="level1">Valid purposes are: 
<p class="level2">ALL, DIGITAL_SIGNATURE, NON_REPUDIATION, KEY_ENCIPHERMENT, DATA_ENCIPHERMENT, KEY_AGREEMENT, KEY_CERT_SIGN, CRL_SIGN, SERVER_AUTH (default), CLIENT_AUTH, CODE_SIGNING, 