Packages.txt says:

    - DEINSTALLDEPENDS:                              
      Remove all packages that require (depend on) the given package.                                 
      This can be used to remove any packages that may have been pulled in                            
      by a given package, e.g. if "make deinstall DEINSTALLDEPENDS=1" is                              
      done in x11/kde, this is likely to remove whole KDE. Works by adding                            
      a "-R" to the pkg_delete command line.      

If we have Packages A and B, such that

	A->C->D->E
	    /
	B---

Will pkg_delete A remove: ACDE ? (Leaving B broken), or AC ? (making a 
						rebuild of A require manual
						intervention - because of
						version reqs, or say, ELF.)

-- 
David Maxwell, david@vex.net|david@maxwell.net -->
If you don't spend energy getting what you want,
	You'll have to spend it dealing with what you get.
					      - Unknown