Editing Character Encoding (section)

=== SFTP ===

The situation for SFTP is similar to the one for FTP. Current versions of the SFTP specifications (beginning with version 4) require filenames to be encoded as UTF-8.

However, the most commonly used SFTP protocol version is version 3 as implemented in OpenSSH. This version of the SFTP specifications does not require UTF-8. In fact it does not say anything about the encoding.
It is however reasonable to assume UTF-8 on those servers for the following reasons:
* The later protocol versions require UTF-8
* The SSH protocol, under which SFTP operates, already requires UTF-8
* Even in version 3 of the protocol, some parts of the protocol already use UTF-8
* The native character set on most modern Unix(-like) operating systems is UTF-8

In essence this means that everywhere where SFTP is available, the necessary infrastructure to use UTF-8 is in place.