Hi,

In message "Re: T_BLKTAG"
    on Sat, 15 Oct 2005 15:34:58 +0900, Charles Mills <cmills / freeshell.org> writes:

|What is T_BLKTAG used for?  I see it in the Ruby sources, but the  
|only place it is used is in ruby.h and gc.c.  No objects with type  
|T_BLKTAG are ever created.

It's sentinel marker to denote non-object value type (T_NODE etc).

							matz.