Shell

undefined:

A shell is a type of system member through which all other members act, front, and (possibly) blend.

Shells are often used to described members in orbital or non-switching systems, in this context it may be similar to a core, masker, or blanket self.

The term shell may also describe a type of member in programmed systems that is meant to hide the system's existence or make it more covert. Shells in this context are often less elaborated, lack agency, and may be fragmentary.

Related Terms
In partitionary systems specifically, a member like this may be called prism.

Systems with a shell may consider themselves monoconscious, hydraconscious, or cephaconscious and may have atrial memory management.

A shell may be frontstuck or even a part of front and serve as a sort of "interface" with the outer world.

History
This term has been used in several contexts, though pinpointing its origin or exact uses is difficult. The term does pop up in more psychiatric perspectives, but reference trails tend to lose themselves, go in circles, or lead back to a handful of sources that are either in some ways problematic or contested or have lacking or even inaccurate definitions of collateral terms.