Where is the DirXML-ADContext set?

I seem to be having trouble finding where it should be set. Which would
explain why it is absent on all users...

I am using 3.61 with the V5 preconfig.

I know I recall seeing it actually being set, but with so many rules,
seem to be having trouble locating it!

I see it in the Pub Create rule, but when does it get set, if you create
a user in AD via the Sub channel?

Wonder if this is another V5 config'ism...