Pathnames MUST adhere to the Universal Naming Convention (UNC). The <sharename> component of a UNC-compliant pathname MUST adhere to the restrictions of a Share Name structure as defined in [MS-FSCC] section 2.1.6, with an additional note that it MAY be subject to the restrictions of file and directory names (section 126.96.36.199.1). The <filename> component of a UNC-compliant pathname MAY be zero or more name components separated by the "\" (backslash) character. All name components of a pathname MUST adhere to the restrictions of file and directory names as specified in section 188.8.131.52.1.
If a pathname points to an object or device in DFS, it is a DFS Path and certain restrictions apply as specified in [MS-DFSC] section 2.2.1. A client that recognizes DFS SHOULD set the SMB_FLAGS2_DFS flag in the SMB Header (section 184.108.40.206) in all SMB requests using a DFS Path, and the server SHOULD resolve it within the DFS namespace.