fvwm does not provide x-window-manager?

[Shaul Karl <shaulk@israsrv.net.il>]

I wonder why fvwm does not provides x-window-manager.
The following is copy and paste from deslect:

dselect - recursive package listing                  mark:+/=/- verbose:v 
help:?
EIOM Pri Section  Package      Description
 **_ Opt x11      twm          Tab window manager                              

 *** Std x11      xfree86-comm X Window System (XFree86) infrastructure
  __ Opt x11      qvwm         Windows95 like window manager for X Window 
System
  __ Opt x11      icewm        A wonderful Win95-OS/2-Motif-like window 
manager
  __ Opt x11      lwm          Lightweight Window Manager
  __ Opt x11      sawmill      a highly configurable window manager for X11
  __ Opt x11      icewm-gnome  A wonderful Win95-OS/2-Motif-like window 
manager



twm          installed;  purge (was: install).  Optional
xfree86-common suggests twm or x-window-manager
xfree86-common suggests twm or x-window-manager
twm provides x-window-manager