Most warranty disclaimer language shouts at you.  The

\href{http://www.law.cornell.edu/ucc/2/2-316}{Uniform Commercial

  Code~\S2-316}, which most of the USA's states and commonwealths have adopted as their local

law, allows disclaimers of warranty, provided that the disclaimer is ``conspicuous''.

There is apparently general acceptance that \textsc{all caps} is the

preferred way to make something conspicuous, and that has over decades worked

its way into the voodoo tradition of warranty disclaimer writing.

That said, there is admittedly some authority under USA law suggesting that

conspicuousness can be established by

capitalization and is absent when a disclaimer has the same typeface as the

terms surrounding it (see \textit{Stevenson v.~TRW, Inc.}, 987 F.2d 288, 296

(5th Cir.~1993)).  While GPLv3's drafters doubted that such authority would

apply to copyright licenses like the GPL, the FSF has nevertheless left

warranty and related disclaimers in \textsc{all caps} throughout all versions

of GPL\@.\footnote{One of the authors of this tutorial, Bradley M.~Kuhn, has

  often suggested the aesthetically preferable compromise of a

  \textsc{specifically designed ``small caps'' font, such as this one, as an

    alternative to} WRITING IN ALL CAPS IN THE DEFAULT FONT (LIKE THIS),

  since the latter adds more ugliness than conspicuousness.  Kuhn once

  engaged in reversion war with a lawyer who disagreed, but that lawyer never

  answered Kuhn's requests for case law that argues THIS IS INHERENTLY MORE

  CONSPICUOUS \textsc{Than this is}.}

Critics have occasionally questioned GPL's enforceability in some jurisdictions because its

disclaimer of warranties is impermissibly broad.  However,

critics

have generally failed to articulate specific precedents in their

jurisdictions that would directly indicate a problem with GPL's warranty

disclaimer.  Meanwhile,

\href{http://www.cisg.law.pace.edu/cisg/text/treaty.html#35}{Article 35 of

  the United Nations Convention on Contracts for the International Sale of

  Goods} (often abbreviated ``CISG'', which

\href{https://treaties.un.org/Pages/ViewDetails.aspx?src=TREATY&id=228&chapter=10&lang=en}{many

  countries have adopted}) permits the disclaimer of warranties, so

jurisdictions adopting this treaty allow some form of warranty

disclaimer\footnote{Scholars continue to debate to what extent CISG applies to software

  licenses.  For example, Diedrich concluded that ``CISG is prima facie

  applicable to international transactions involving the transfer of computer

  software for a price'', but Sono disagrees with this ``prevailing view'',

  presenting an ``analysis [that] restricts the applicability of the CISG to

  software transactions by excluding `license contracts'''.  (See

  \href{http://www.cisg.law.pace.edu/cisg/biblio/diedrich1.html}{Frank

    Diedrich, \textit{The CISG and Computer Software Revisited}}, 6 Vindobona

  Journal of International Commercial Law and Arbitration, Supplement 55--75

  (2002), and

\href{http://www.cisg.law.pace.edu/cisg/biblio/sono6.html}{Hiroo Sono,

  \textit{The Applicability and Non-Applicability of the CISG to Software