Public File Naming Conventions
File naming structure should be identifiable but have no pattern that can assist in indexing the folder.
Examples of file naming: 2016-floods-action-plan-amendment-15 can be also APA_15-Great-Floods.
As long as there is never a logical pattern used the file will have natural obscurity from the public and search engines.
Following this naming methodology you can reduce public awareness to published documents.
You should also use cloud services and change the master folder often to increase difficult for indexing. Master folder names should be random character format, example: "hxjmbnxv".