\section{Track Your Changes and Releases}

As explained in further detail below, the most important component of GPL

compliance is the one most often ignored: proper inclusion of CCS in all

distributions  of GPL'd

software.  To comply with GPL's CCS requirements, the distributor

\textit{must} always know precisely what sources generated a given binary

distribution.

In an unfortunately large number of our enforcement cases, the violating

company's engineering team had difficulty reconstructing the CCS

for binaries distributed by the company.  Here are three simple rules to

\begin{itemize}

\item Ensure that your

developers are using revision control systems properly.

\item Have developers mark or ``tag'' the full source tree corresponding to

  builds distributed to customers

\item Check that your developers store all parts of the software

development in the revision control system, including {\sc readme}s, build

scripts, engineers' notes, and documentation.

Meanwhile, despite many calls by the FSF (and others) for those licensors who

explicitly use this section to come forward and explain their reasoning, no

one ever did.  Furthermore, research conducted during the GPLv3 drafting

process found exactly one licensor who had invoked this section to add an

explicit geographical distribution limitation, and the reasoning for that one

invocation was not fitting with FSF's intended spirit of GPLv2~\S8.  As such,

GPLv2~\S8 was not included at all in GPLv3.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\chapter{Odds, Ends, and Absolutely No Warranty}

GPLv2~\S\S0--7 constitute the freedom-defending terms of the GPLv2.  The remainder

liability.

\section{GPLv2~\S9: FSF as Stewards of GPL}

\label{GPLv2s9}

FSF reserves the exclusive right to publish future versions of the GPL\@;

GPLv2~\S9 expresses this.  While the stewardship of the copyrights on the body

of GPL'd software around the world is shared among thousands of

individuals and organizations, the license itself needs a single steward.

Forking of the code is often regrettable but basically innocuous.  Forking

of licensing is disastrous.

The remaining patent licensing in GPLv3 deals with patent licenses that are

granted by conveyance.  The licensing is not as complete or far reaching as

the contributor patent licenses discussed in the preceding section.

The term ``patent license,'' as used in GPLv3~\S11\P4--6, is not meant to be

confined to agreements formally identified or classified as patent licenses.

GPLv3~\S11\P3  makes this clear by defining ``patent

license,'' for purposes of the subsequent three paragraphs, as ``any express

agreement or commitment, however denominated, not to enforce a patent

(such as an express permission to practice a patent or covenant not to

sue for patent infringement)''

% The definition does not include patent licenses that arise by

% implication or operation of law, because the third through fifth paragraphs

% of section 11 are specifically concerned with explicit promises that purport

% to be legally enforceable.

GPLv3~\S11\P5 is commonly called GPLv3's downstream shielding provision.  It

responds particularly to the problem of exclusive deals between patent

holders and distributors, which threaten to distort the free software

distribution system in a manner adverse to developers and users.  The

fundamental idea is to make a trade-off between assuring a patent license for

downstream and making  (possibly patent-encumbered) CCS publicly available.