Kerberos password change specification

[Bruno Medeiros]

Hello.

I was wondering where is the specification for the original Kerberos 
Change Password protocol, as I could not find it so far. RFC 3244 only 
details the Windows extension, and for what I've seen of RFC 1510, there 
is no mention of how the Password change actually works. (or I've missed 
it somehow)
Why does RFC 1510 refer to the password change service (example: "(The 
password-changing request must not be honored unless the requester can 
provide the old password (the user's current secret key)"), but not 
actually specify how it works, or refer to some other document that does?

I've searched a bit more and found these documents:
http://tools.ietf.org/html/draft-ietf-krb-wg-kerberos-set-passwd-00
Are these the specifications? If so, why are these still drafts, whereas 
Kerberos is fairly old and mature?

I'm not familiar with Kerberos history unfortunately, so I'm confused by 
this.

Regards
-- 
Bruno Medeiros