Address Verification then creates a JSON file called

FileSetsInfo.json

within the parent directory on the same level as

FileSetA

and

FileSetB

.

FileSetsInfo.json

identifies the currently active file set. It is therefore necessary for Address Verification to have write access to the parent file set directory. If Address Verification cannot create or write to the JSON file, initialization will abort.

The JSON file contents may look like this:

{ "FileSetAState": "InUse", "FileSetBState": "Unused" }

In this example,

FileSetA

is currently active.

FileSetB

is currently unused.

The

FileSetsInfo.json

file persists on disk after Address Verification is deinitialized. If Address Verification finds this file during initialization it will base the decision on which file set to use on the file contents. If the JSON file has valid contents, this supersedes the rules outlined above. However, if the JSON file instructs Address Verification to use a file set for which no sub-directory is present, initialization will abort. Similarly, if the JSON file does not have the right format or has invalid content, initialization will abort.