.
     2 <title>GNU Free Documentation License</title>
 
     3 <subtitle>Version 1.2, November 2002</subtitle>
 
     5 <blockquote id="fsf-copyright">
 
     6  <para>Copyright (C) 2000,2001,2002  Free Software Foundation, Inc.
 
     7 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
     8 Everyone is permitted to copy and distribute verbatim copies
 
     9 of this license document, but changing it is not allowed.</para>
 
    12 <section id="gfdl-0"><title>PREAMBLE</title>
 
    14 <para>The purpose of this License is to make a manual, textbook, or
 
    15 other functional and useful document "free" in the sense of freedom: to
 
    16 assure everyone the effective freedom to copy and redistribute it, with
 
    17 or without modifying it, either commercially or noncommercially.
 
    18 Secondarily, this License preserves for the author and publisher a way
 
    19 to get credit for their work, while not being considered responsible for
 
    20 modifications made by others.</para>
 
    22 <para>This License is a kind of "copyleft", which means that derivative
 
    23 works of the document must themselves be free in the same sense.  It
 
    24 complements the GNU General Public License, which is a copyleft license
 
    25 designed for free software.</para>
 
    27 <para>We have designed this License in order to use it for manuals for
 
    28 free software, because free software needs free documentation: a free
 
    29 program should come with manuals providing the same freedoms that the
 
    30 software does.  But this License is not limited to software manuals; it
 
    31 can be used for any textual work, regardless of subject matter or
 
    32 whether it is published as a printed book.  We recommend this License
 
    33 principally for works whose purpose is instruction or reference.</para>
 
    36 <section id="gfdl-1"><title>APPLICABILITY AND DEFINITIONS</title>
 
    38 <para id="gfdl-doc">This License applies to any manual or other work, in
 
    39 any medium, that contains a notice placed by the copyright holder saying
 
    40 it can be distributed under the terms of this License.  Such a notice
 
    41 grants a world-wide, royalty-free license, unlimited in duration, to use
 
    42 that work under the conditions stated herein.  The "Document", below,
 
    43 refers to any such manual or work.  Any member of the public is a
 
    44 licensee, and is addressed as "you".  You accept the license if you
 
    45 copy, modify or distribute the work in a way requiring permission under
 
    48 <para id="gfdl-mod-ver">A "Modified Version" of the Document means any
 
    49 work containing the Document or a portion of it, either copied verbatim,
 
    50 or with modifications and/or translated into another language.</para>
 
    52 <para id="gfdl-secnd-sect">A "Secondary Section" is a named appendix or
 
    53 a front-matter section of the Document that deals exclusively with the
 
    54 relationship of the publishers or authors of the Document to the
 
    55 Document's overall subject (or to related matters) and contains nothing
 
    56 that could fall directly within that overall subject.  (Thus, if the
 
    57 Document is in part a textbook of mathematics, a Secondary Section may
 
    58 not explain any mathematics.)  The relationship could be a matter of
 
    59 historical connection with the subject or with related matters, or of
 
    60 legal, commercial, philosophical, ethical or political position
 
    61 regarding them.</para>
 
    63 <para id="gfdl-inv-sect">The "Invariant Sections" are certain Secondary
 
    64 Sections whose titles are designated, as being those of Invariant
 
    65 Sections, in the notice that says that the Document is released under
 
    66 this License.  If a section does not fit the above definition of
 
    67 Secondary then it is not allowed to be designated as Invariant.  The
 
    68 Document may contain zero Invariant Sections.  If the Document does not
 
    69 identify any Invariant Sections then there are none.</para>
 
    71 <para id="gfdl-cov-text">The "Cover Texts" are certain short passages of
 
    72 text that are listed, as Front-Cover Texts or Back-Cover Texts, in the
 
    73 notice that says that the Document is released under this License.  A
 
    74 Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at
 
    77 <para id="gfdl-transparent">A "Transparent" copy of the Document means a
 
    78 machine-readable copy, represented in a format whose specification is
 
    79 available to the general public, that is suitable for revising the
 
    80 document straightforwardly with generic text editors or (for images
 
    81 composed of pixels) generic paint programs or (for drawings) some widely
 
    82 available drawing editor, and that is suitable for input to text
 
    83 formatters or for automatic translation to a variety of formats suitable
 
    84 for input to text formatters.  A copy made in an otherwise Transparent
 
    85 file format whose markup, or absence of markup, has been arranged to
 
    86 thwart or discourage subsequent modification by readers is not
 
    87 Transparent.  An image format is not Transparent if used for any
 
    88 substantial amount of text.  A copy that is not "Transparent" is called
 
    91 <para>Examples of suitable formats for Transparent copies include plain
 
    92 ASCII without markup, Texinfo input format, LaTeX input format, SGML or
 
    93 XML using a publicly available DTD, and standard-conforming simple HTML,
 
    94 PostScript or PDF designed for human modification.  Examples of
 
    95 transparent image formats include PNG, XCF and JPG.  Opaque formats
 
    96 include proprietary formats that can be read and edited only by
 
    97 proprietary word processors, SGML or XML for which the DTD and/or
 
    98 processing tools are not generally available, and the machine-generated
 
    99 HTML, PostScript or PDF produced by some word processors for output
 
   100 purposes only.</para>
 
   102 <para id="gfdl-title-page">The "Title Page" means, for a printed book,
 
   103 the title page itself, plus such following pages as are needed to hold,
 
   104 legibly, the material this License requires to appear in the title page.
 
   105 For works in formats which do not have any title page as such, "Title
 
   106 Page" means the text near the most prominent appearance of the work's
 
   107 title, preceding the beginning of the body of the text.</para>
 
   109 <para id="gfdl-entitled">A section "Entitled XYZ" means a named subunit
 
   110 of the Document whose title either is precisely XYZ or contains XYZ in
 
   111 parentheses following text that translates XYZ in another language.
 
   112 (Here XYZ stands for a specific section name mentioned below, such as
 
   113 "Acknowledgements", "Dedications", "Endorsements", or "History".)  To
 
   114 "Preserve the Title" of such a section when you modify the Document
 
   115 means that it remains a section "Entitled XYZ" according to this
 
   118 <para>The Document may include Warranty Disclaimers next to the notice
 
   119 which states that this License applies to the Document.  These Warranty
 
   120 Disclaimers are considered to be included by reference in this License,
 
   121 but only as regards disclaiming warranties: any other implication that
 
   122 these Warranty Disclaimers may have is void and has no effect on the
 
   123 meaning of this License.</para>
 
   126 <section id="gfdl-2"><title>VERBATIM COPYING</title>
 
   128 <para>You may copy and distribute the Document in any medium, either
 
   129 commercially or noncommercially, provided that this License, the
 
   130 copyright notices, and the license notice saying this License applies to
 
   131 the Document are reproduced in all copies, and that you add no other
 
   132 conditions whatsoever to those of this License.  You may not use
 
   133 technical measures to obstruct or control the reading or further copying
 
   134 of the copies you make or distribute.  However, you may accept
 
   135 compensation in exchange for copies.  If you distribute a large enough
 
   136 number of copies you must also follow the conditions in section 3.
 
   139 <para>You may also lend copies, under the same conditions stated above,
 
   140 and you may publicly display copies.</para>
 
   143 <section id="gfdl-3"><title>COPYING IN QUANTITY</title>
 
   145 <para>If you publish printed copies (or copies in media that commonly
 
   146 have printed covers) of the Document, numbering more than 100, and the
 
   147 Document's license notice requires Cover Texts, you must enclose the
 
   148 copies in covers that carry, clearly and legibly, all these Cover Texts:
 
   149 Front-Cover Texts on the front cover, and Back-Cover Texts on the back
 
   150 cover.  Both covers must also clearly and legibly identify you as the
 
   151 publisher of these copies.  The front cover must present the full title
 
   152 with all words of the title equally prominent and visible.  You may add
 
   153 other material on the covers in addition.  Copying with changes limited
 
   154 to the covers, as long as they preserve the title of the Document and
 
   155 satisfy these conditions, can be treated as verbatim copying in other
 
   158 <para>If the required texts for either cover are too voluminous to fit
 
   159 legibly, you should put the first ones listed (as many as fit
 
   160 reasonably) on the actual cover, and continue the rest onto adjacent
 
   163 <para>If you publish or distribute Opaque copies of the Document
 
   164 numbering more than 100, you must either include a machine-readable
 
   165 Transparent copy along with each Opaque copy, or state in or with each
 
   166 Opaque copy a computer-network location from which the general
 
   167 network-using public has access to download using public-standard
 
   168 network protocols a complete Transparent copy of the Document, free of
 
   169 added material.  If you use the latter option, you must take reasonably
 
   170 prudent steps, when you begin distribution of Opaque copies in quantity,
 
   171 to ensure that this Transparent copy will remain thus accessible at the
 
   172 stated location until at least one year after the last time you
 
   173 distribute an Opaque copy (directly or through your agents or retailers)
 
   174 of that edition to the public.</para>
 
   176 <para>It is requested, but not required, that you contact the authors of
 
   177 the Document well before redistributing any large number of copies, to
 
   178 give them a chance to provide you with an updated version of the
 
   182 <section id="gfdl-4"><title>MODIFICATIONS</title>
 
   184 <para>You may copy and distribute a Modified Version of the Document
 
   185 under the conditions of sections 2 and 3 above, provided that you
 
   186 release the Modified Version under precisely this License, with the
 
   187 Modified Version filling the role of the Document, thus licensing
 
   188 distribution and modification of the Modified Version to whoever
 
   189 possesses a copy of it.  In addition, you must do these things in the
 
   190 Modified Version:</para>
 
   192 <orderedlist id="gfdl-modif-cond" numeration="upperalpha">
 
   193 <listitem><simpara>Use in the Title Page (and on the covers, if any) a
 
   194   title distinct from that of the Document, and from those of previous
 
   195   versions (which should, if there were any, be listed in the History
 
   196   section of the Document).  You may use the same title as a previous
 
   197   version if the original publisher of that version gives permission.
 
   198 </simpara></listitem>
 
   199 <listitem><simpara>List on the Title Page, as authors, one or more
 
   200   persons or entities responsible for authorship of the modifications in
 
   201   the Modified Version, together with at least five of the principal
 
   202   authors of the Document (all of its principal authors, if it has fewer
 
   203   than five), unless they release you from this requirement.
 
   204 </simpara></listitem>
 
   205 <listitem><simpara>State on the Title page the name of the publisher of
 
   206   the Modified Version, as the publisher.</simpara></listitem>
 
   207 <listitem><simpara>Preserve all the copyright notices of the Document.
 
   208 </simpara></listitem>
 
   209 <listitem><simpara>Add an appropriate copyright notice for your
 
   210   modifications adjacent to the other copyright notices.
 
   211 </simpara></listitem>
 
   212 <listitem><simpara>Include, immediately after the copyright notices, a
 
   213   license notice giving the public permission to use the Modified
 
   214   Version under the terms of this License, in the form shown in the
 
   215   <link linkend="gfdl-addendum">Addendum</link> below.
 
   216 </simpara></listitem>
 
   217 <listitem><simpara>Preserve in that license notice the full lists of
 
   218   Invariant Sections and required Cover Texts given in the Document's
 
   219   license notice.</simpara></listitem>
 
   220 <listitem><simpara>Include an unaltered copy of this License.
 
   221 </simpara></listitem>
 
   222 <listitem><simpara>Preserve the section Entitled "History", Preserve its
 
   223   Title, and add to it an item stating at least the title, year, new
 
   224   authors, and publisher of the Modified Version as given on the Title
 
   225   Page.  If there is no section Entitled "History" in the Document,
 
   226   create one stating the title, year, authors, and publisher of the
 
   227   Document as given on its Title Page, then add an item describing the
 
   228   Modified Version as stated in the previous sentence.
 
   229 </simpara></listitem>
 
   230 <listitem><simpara>Preserve the network location, if any, given in the
 
   231   Document for public access to a Transparent copy of the Document, and
 
   232   likewise the network locations given in the Document for previous
 
   233   versions it was based on.  These may be placed in the "History"
 
   234   section.  You may omit a network location for a work that was
 
   235   published at least four years before the Document itself, or if the
 
   236   original publisher of the version it refers to gives permission.
 
   237 </simpara></listitem>
 
   238 <listitem><simpara>For any section Entitled "Acknowledgements" or
 
   239   "Dedications", Preserve the Title of the section, and preserve in the
 
   240   section all the substance and tone of each of the contributor
 
   241   acknowledgements and/or dedications given therein.
 
   242 </simpara></listitem>
 
   243 <listitem><simpara>Preserve all the Invariant Sections of the Document,
 
   244   unaltered in their text and in their titles.  Section numbers or the
 
   245   equivalent are not considered part of the section titles.
 
   246 </simpara></listitem>
 
   247 <listitem><simpara>Delete any section Entitled "Endorsements".
 
   248   Such a section may not be included in the Modified Version.
 
   249 </simpara></listitem>
 
   250 <listitem><simpara>Do not retitle any existing section to be Entitled
 
   251   "Endorsements" or to conflict in title with any Invariant Section.
 
   252 </simpara></listitem>
 
   253 <listitem><simpara>Preserve any Warranty Disclaimers.
 
   254 </simpara></listitem>
 
   257 <para>If the Modified Version includes new front-matter sections or
 
   258 appendices that qualify as Secondary Sections and contain no material
 
   259 copied from the Document, you may at your option designate some or all
 
   260 of these sections as invariant.  To do this, add their titles to the
 
   261 list of Invariant Sections in the Modified Version's license notice.
 
   262 These titles must be distinct from any other section titles.</para>
 
   264 <para>You may add a section Entitled "Endorsements", provided it
 
   265 contains nothing but endorsements of your Modified Version by various
 
   266 parties--for example, statements of peer review or that the text has
 
   267 been approved by an organization as the authoritative definition of a
 
   270 <para>You may add a passage of up to five words as a Front-Cover Text,
 
   271 and a passage of up to 25 words as a Back-Cover Text, to the end of the
 
   272 list of Cover Texts in the Modified Version.  Only one passage of
 
   273 Front-Cover Text and one of Back-Cover Text may be added by (or through
 
   274 arrangements made by) any one entity.  If the Document already includes
 
   275 a cover text for the same cover, previously added by you or by
 
   276 arrangement made by the same entity you are acting on behalf of, you may
 
   277 not add another; but you may replace the old one, on explicit permission
 
   278 from the previous publisher that added the old one.</para>
 
   280 <para>The author(s) and publisher(s) of the Document do not by this
 
   281 License give permission to use their names for publicity for or to
 
   282 assert or imply endorsement of any Modified Version.</para>
 
   285 <section id="gfdl-5"><title>COMBINING DOCUMENTS</title>
 
   287 <para>You may combine the Document with other documents released under
 
   288 this License, under the terms defined in <link linkend="gfdl-4">section
 
   289 4</link> above for modified versions, provided that you include in the
 
   290 combination all of the Invariant Sections of all of the original
 
   291 documents, unmodified, and list them all as Invariant Sections of your
 
   292 combined work in its license notice, and that you preserve all their
 
   293 Warranty Disclaimers.</para>
 
   295 <para>The combined work need only contain one copy of this License, and
 
   296 multiple identical Invariant Sections may be replaced with a single
 
   297 copy.  If there are multiple Invariant Sections with the same name but
 
   298 different contents, make the title of each such section unique by adding
 
   299 at the end of it, in parentheses, the name of the original author or
 
   300 publisher of that section if known, or else a unique number.  Make the
 
   301 same adjustment to the section titles in the list of Invariant Sections
 
   302 in the license notice of the combined work.</para>
 
   304 <para>In the combination, you must combine any sections Entitled
 
   305 "History" in the various original documents, forming one section
 
   306 Entitled "History"; likewise combine any sections Entitled
 
   307 "Acknowledgements", and any sections Entitled "Dedications".  You must
 
   308 delete all sections Entitled "Endorsements".</para>
 
   311 <section id="gfdl-6"><title>COLLECTIONS OF DOCUMENTS</title>
 
   313 <para>You may make a collection consisting of the Document and other
 
   314 documents released under this License, and replace the individual copies
 
   315 of this License in the various documents with a single copy that is
 
   316 included in the collection, provided that you follow the rules of this
 
   317 License for verbatim copying of each of the documents in all other
 
   320 <para>You may extract a single document from such a collection, and
 
   321 distribute it individually under this License, provided you insert a
 
   322 copy of this License into the extracted document, and follow this
 
   323 License in all other respects regarding verbatim copying of that
 
   327 <section id="gfdl-7"><title>AGGREGATION WITH INDEPENDENT WORKS</title>
 
   329 <para>A compilation of the Document or its derivatives with other
 
   330 separate and independent documents or works, in or on a volume of a
 
   331 storage or distribution medium, is called an "aggregate" if the
 
   332 copyright resulting from the compilation is not used to limit the legal
 
   333 rights of the compilation's users beyond what the individual works
 
   334 permit.  When the Document is included in an aggregate, this License does
 
   335 not apply to the other works in the aggregate which are not themselves
 
   336 derivative works of the Document.</para>
 
   338 <para>If the Cover Text requirement of section 3 is applicable to these
 
   339 copies of the Document, then if the Document is less than one half of
 
   340 the entire aggregate, the Document's Cover Texts may be placed on covers
 
   341 that bracket the Document within the aggregate, or the electronic
 
   342 equivalent of covers if the Document is in electronic form.  Otherwise
 
   343 they must appear on printed covers that bracket the whole
 
   347 <section id="gfdl-8"><title>TRANSLATION</title>
 
   349 <para>Translation is considered a kind of modification, so you may
 
   350 distribute translations of the Document under the terms of section 4.
 
   351 Replacing Invariant Sections with translations requires special
 
   352 permission from their copyright holders, but you may include
 
   353 translations of some or all Invariant Sections in addition to the
 
   354 original versions of these Invariant Sections.  You may include a
 
   355 translation of this License, and all the license notices in the
 
   356 Document, and any Warranty Disclaimers, provided that you also include
 
   357 the original English version of this License and the original versions
 
   358 of those notices and disclaimers.  In case of a disagreement between the
 
   359 translation and the original version of this License or a notice or
 
   360 disclaimer, the original version will prevail.</para>
 
   362 <para>If a section in the Document is Entitled "Acknowledgements",
 
   363 "Dedications", or "History", the requirement (section 4) to Preserve its
 
   364 Title (section 1) will typically require changing the actual
 
   368 <section id="gfdl-9"><title>TERMINATION</title>
 
   370 <para>You may not copy, modify, sublicense, or distribute the Document
 
   371 except as expressly provided for under this License.  Any other attempt
 
   372 to copy, modify, sublicense or distribute the Document is void, and will
 
   373 automatically terminate your rights under this License.  However,
 
   374 parties who have received copies, or rights, from you under this License
 
   375 will not have their licenses terminated so long as such parties remain
 
   376 in full compliance.</para>
 
   379 <section id="gfdl-10"><title>FUTURE REVISIONS OF THIS LICENSE</title>
 
   381 <para>The Free Software Foundation may publish new, revised versions of
 
   382 the GNU Free Documentation License from time to time.  Such new versions
 
   383 will be similar in spirit to the present version, but may differ in
 
   384 detail to address new problems or concerns.  See
 
   385 http://www.gnu.org/copyleft/.</para>
 
   387 <para>Each version of the License is given a distinguishing version
 
   388 number.  If the Document specifies that a particular numbered version of
 
   389 this License "or any later version" applies to it, you have the option
 
   390 of following the terms and conditions either of that specified version
 
   391 or of any later version that has been published (not as a draft) by the
 
   392 Free Software Foundation.  If the Document does not specify a version
 
   393 number of this License, you may choose any version ever published (not
 
   394 as a draft) by the Free Software Foundation.</para>
 
   397 <section id="gfdl-addendum"><title>ADDENDUM: How to use this License for
 
   398   your documents</title>
 
   400 <para>To use this License in a document you have written, include a copy
 
   401 of the License in the document and put the following copyright and
 
   402 license notices just after the title page:</para>
 
   404 <blockquote id="copyright-sample"><para>
 
   405     Copyright (c)  YEAR  YOUR NAME.
 
   406     Permission is granted to copy, distribute and/or modify this document
 
   407     under the terms of the GNU Free Documentation License, Version 1.2
 
   408     or any later version published by the Free Software Foundation;
 
   409     with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
 
   410     A copy of the license is included in the section entitled "GNU
 
   411     Free Documentation License".
 
   414 <para>If you have Invariant Sections, Front-Cover Texts and Back-Cover
 
   415 Texts, replace the "with...Texts." line with this:</para>
 
   417 <blockquote id="inv-cover-sample"><para>
 
   418     with the Invariant Sections being LIST THEIR TITLES, with the
 
   419     Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
 
   422 <para>If you have Invariant Sections without Cover Texts, or some other
 
   423 combination of the three, merge those two alternatives to suit the
 
   426 <para>If your document contains nontrivial examples of program code, we
 
   427 recommend releasing these examples in parallel under your choice of free
 
   428 software license, such as the GNU General Public License, to permit
 
   429 their use in free software.</para>