mutt header display question

[Paul Mackinney <paul@mackinney.net>]

I've been trying to write a mailfilter rule, nothing worked. Finally I
noticed that while mutt displays the From header as

  AmikaGuardian Server <abuse@speakeasy.net>

This showed the same whether with the full headers toggled on or off.
Just a minute ago, when I just catted a sample msg file in the shell it
showed as

  AmikaGuardian (TM) Server <abuse@speakeasy.net>

So now I understand why my filter wasn't working. Can someone explain to
me why mutt's display omitted the parenthesized bit?

TIA, PM
-- 
Paul Mackinney
paul@mackinney.net