Shared Parameters, "Type" versus "Instance".

Here is a lot of great information on shared parameters, from Steve Stafford's blog. Make sure to check his other posts on the subject, linked at the end of the post.

The one thing Steve does not seem to talk about is how do you change a shared parameter from "type" to "instance". One of our Revit model manager just told me she was editing door families and changing the "Frame Detail" parameter from Type to Instance. It just hit me: if a shared parameter comes from a family, you can edit it in the families of the elements it is assigned to; for examples, doors.

I need to further investigate this, but it appears a great feature to me, whom I have been always very confused about how rigid shared parameters seem to be.