About scanning files in Symantec Protection Engine using different services/APIs
Symantec Protection Engine now includes services for supporting Insight,better categorization of threats and unscannable file handling features. These services provide Insight information, additional threat information and unscannable file count in ICAP response. For more information, see the Symantec Protection Engine Software Developer's Guide.
The -api option specifies what service to use to scan the file. The default setting is to use the old API to scan files.