ADFS : Selecting claim that's not in the default drop down

When you want to edit the claims rules for a CP or RP in ADFS v2.0, you sometimes need to select an LDAP attribute that's not in the default drop down list.

I've always done this via a custom claim, But then I read this post: Active Directory attribute store: Require custom claim rule to access other attributes?.

The drop down actually allows free-form (not that that is obvious). In case the link disappears, this is how:

"Edit Claims Rules / Add Rule / Send LDAP Attributes as Claims".
Don't select the drop-down, just click in the white space of the grid.
If the box turns dark blue, click again.
Away you go - you can now enter any attribute you like.

This also works for the "Outgoing Claims Type" box.

Enjoy!