Named streams are used to store Mac OS X extended attributes and can be leveraged to avoid using AppleDoublefiles to store the data fork and the resource fork of legacy Mac files.
Mac OS X Server v10.5 and v10.6, as well as many Network Attached Storage (NAS) devices, support named streams when you connect to them via SMB.
Microsoft Windows servers with NTFS-formatted hard drives also support named streams when you connect to them via SMB; named streams are called “Alternate Data Streams” in Windows.
Mac OS X v10.5 and v10.6 clients automatically enable named streams support when they have a SMB connection to a Mac OS X Server v10.5 or v10.6-based server.
Mac OS X v10.6 clients automatically enable named streams over SMB when the NAS or Windows server claims to support it. See below for details about how to activate Mac OS X v10.5 client support of named streams over SMB connections to a NAS or Windows server.