[Standards] JID Escaping

[Mats Bengtsson]

While implementing XEP-0106: JID Escaping I got puzzled.
Consider the following unescaped JID which a user may input:

mats at home.se/coci at home.se/mats at home.se/coci

The question is to apply escaping on the node part as defined in the XEP
but first it must be separated into node+domain+resource parts.
However, I see three ways to do this:

First:
node:       mats
domain:   home.se
resource: coci at home.se/mats at home.se/coci

Second:
node:       mats\40home.se\2fcoci
domain:   home.se
resource: mats at home.se/coci

Third:
node:       mats\40home.se\2fcoci\40home.se\2fmats
domain:   home.se
resource:  coci

The key is that it is impossible to identify the "real" "@".
Any thoughts?

Mats