Fully Qualified Name

To uniquely identify a given key within the entire key namespace, its fully qualified name (FQN) is used. The FQN MUST consist of the Base Name of the key and the name of all of its parent keys all the way to the root of the tree, using the "\" character as a hierarchy separator. The Base Name of the first key in the FQN is called a Root Key or Predefined Key. The Root Keys are well-known keys that all implementations of this protocol MUST support. Section defines the Predefined Keys.

For example, the key MountedDevices is a subkey of HKEY_LOCAL_MACHINE, as shown in the following example.


The FQN for MountedDevices is HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices.

The Root Key in the FQN for MountedDevices is HKEY_LOCAL_MACHINE.

The uniqueness of the FQN is relative to the client when the Root Key in the FQN is HKEY_CURRENT_USER or HKEY_CLASSES_ROOT. The server MUST dynamically map subkeys of the HKEY_USERS predefined key as the HKEY_CURRENT_USER and HKEY_CLASSES_ROOT root keys for each client request to operate on the HKEY_CURRENT_USER or HKEY_CLASSES_ROOT root keys. As a result, when different clients open the HKEY_CURRENT_USER or HKEY_CLASSES_ROOT root keys, the same FQN will represent different keys (see

None of the methods in the remote registry protocol accept a key FQN as a parameter. All key name parameters use the Relative Name (section