In UNIX, an exclude list is implemented by creating an exclude_list file with the suffix:
.<policyname>
or
.<policyname>.<schedulename>
The following are two examples for a policy named wkstations that contains a schedule named fulls:
/usr/openv/netbackup/exclude_list.wkstations
/usr/openv/netbackup/exclude_list.wkstations.fulls
The first file affects all scheduled backups in the policy named wkstations.
The second file affects all scheduled backups in the policy named wkstations whose schedule is named fulls.
For a given backup, NetBackup uses only one exclude list with the most specific name. For the above examples, if the two files exist, NetBackup will override the former with the latter and use only:
/usr/openv/netbackup/exclude_list.wkstations.fulls
here is another useful link describing about exclude list
http://enterpriseunix.blogspot.com/2007/11/veritas-netbackup-part-4-exclude-lists.html