WM_ICON_NAME differences with xterm

[Jeremy C. Reed]

I use version v2.6.1. (I would check a newer version, but it appears that
the change log doesn't mention any reason for my question.)

Why does xterm and rxvt act differently?

rxvt -name NAME -title TITLE
  WM_CLASS(STRING) = "NAME", "XTerm"
  WM_ICON_NAME(STRING) = "TITLE"
  WM_NAME(STRING) = "TITLE"

xterm -name NAME -title TITLE
  WM_CLASS(STRING) = "NAME", "XTerm"
  WM_ICON_NAME(STRING) = "NAME"
  WM_NAME(STRING) = "TITLE"
(xterm version with XFree86 Version 3.3.6.)

If this is covered in the past, please let me know.
Please point me to the list archives.

Thanks,

  Jeremy C. Reed
  http://www.reedmedia.net/
  http://bsd.reedmedia.net/