Stamps, Guards and Parents

Hi all,

Apologies for cross-posting.

I have a quick question. Is anyone aware of any capability patterns or
situations in which an object is required to be stamped* by an object
other than its parent? 

If I understand correctly, Jed's "MyCap?" operation is a specific
example in which it is impossible for this situation to arise. I believe
the KeyKOS "factory" implementation is similar, in that it doesn't allow
an object to be "stamped" by anyone other than its parent. Is that
right?

* Here, "stamped" refers to the act of marking an object with a
particular "trademark" which can then be checked for by corresponding a
"guard" object. The terminology I've adopted here comes from E.

Cheers

Toby