[Users] A question about header insertion...

[nick]

I'm trying to insert a Remote-Party-ID header into my INVITE messages, 
but I'm finding that when I do so, it's ending up further down in the 
message than it should be. After the Content Type header in fact.

How is it decided where to insert the header, is it based on the time 
that the insertion of the header happens during the processing of the 
invite?

Can I specify that it be inserted before the content type header in some 
way? (I didn't see this as an option..)