scp/sftp using IPv6 address, any ambiguity?

[Yong Ni <yni%cisco.com@localhost>]

Hi,

For scp and sftp (used in the command line mode), we provide the src/dst 
path in the form of
   [[user@]host[#port]:]file_or_dir

In case of IPv6 address, the host itself could contain multiple ":". 
How do we solve the ambiguity here?  The problem is worsen when the 
filename containing ":" is allowed in some file system.  For example:
       guest@FFF1::FFFF2:FFF3:FFF4
Can you tell which part is what?  I was under the impression people uses 
"[]"  to group ipv6 address.  However, is there a document somewhere 
about this?

thanks,
Yong