which sftp protocol is openssh or sftp-server using or support?

Hi,

After reading the source code of openssh and man page of sftp.

In sftp.h it define

27 /*
28  * draft-ietf-secsh-filexfer-01.txt
29  */
30
31 /* version */
32 #define SSH2_FILEXFER_VERSION       3

and In the end of the man page,

T. Ylonen and S. Lehtinen, SSH File Transfer Protocol,
draft-ietf-secsh-filexfer-00.txt, January 2001, work in progress
material.

In wikipedia of "SSH File Transfer Protocal", I notice
draft-ietf-secsh-filexfer-00.txt and draft-ietf-secsh-filexfer-01.txt
are related to the sftp protocal version 3.

So do the openssh is using sftp protocol version 3  or is it only
support up to the sftp protocol version 3 ?

Best Regards,