The EXIT_CHAIN is a linked list of functions to be called at program shut down.

The lower word is the offset in the code segment for the shut down process of the link. If this word has a value of zero, the link is ignored and processing will continue with the next link. (I'm not sure why anyone would want to waste code with a NULL link.)

The high word is the offset to the next link in the chain. If this word has a value of zero, it indicates no further links are in the chain.

See also Terminate and AddExitProc.