Higher numbered rules take precedence over lower numbered rules.
Imagine you have a list of files that list which files to backup and each policy rule adds (include rules) or removes (exclude rules) items from that list. You apply rules starting from rule #1 and proceeding to the last rule.
Here's an example policy:
- Include *.*
- Apply all rules in "Default Policy"
- Exclude *.mp3;*.m4a
So in the example the first rule, include *.*, tells it to put every file on "the list." The second rule applies every rule in the "Default Policy" (which excludes stuff like temporary files and browser cache). The third rule is then applied so it removes all .mp3 and .m4a files from "the list."
Once you have the filter right (verify using the "Visualize" feature) then you can tell the server to "destroy excluded files" on the Versioning tab of the Options page. The next time the backups runs it will destroy any data you've excluded from the backup set. Hence it's a good idea to check if the policy looks correct using the "Visualize" feature.