472 lines · plain
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later2 3.. _fdl:4 5******************************6GNU Free Documentation License7******************************8 9 10.. _fdl-preamble:11 120. PREAMBLE13===========14 15The purpose of this License is to make a manual, textbook, or other16written document "free" in the sense of freedom: to assure everyone the17effective freedom to copy and redistribute it, with or without modifying18it, either commercially or noncommercially. Secondarily, this License19preserves for the author and publisher a way to get credit for their20work, while not being considered responsible for modifications made by21others.22 23This License is a kind of "copyleft", which means that derivative works24of the document must themselves be free in the same sense. It25complements the GNU General Public License, which is a copyleft license26designed for free software.27 28We have designed this License in order to use it for manuals for free29software, because free software needs free documentation: a free program30should come with manuals providing the same freedoms that the software31does. But this License is not limited to software manuals; it can be32used for any textual work, regardless of subject matter or whether it is33published as a printed book. We recommend this License principally for34works whose purpose is instruction or reference.35 36 37.. _fdl-section1:38 391. APPLICABILITY AND DEFINITIONS40================================41 42 43.. _fdl-document:44 45This License applies to any manual or other work that contains a notice46placed by the copyright holder saying it can be distributed under the47terms of this License. The "Document", below, refers to any such manual48or work. Any member of the public is a licensee, and is addressed as49"you".50 51 52.. _fdl-modified:53 54A "Modified Version" of the Document means any work containing the55Document or a portion of it, either copied verbatim, or with56modifications and/or translated into another language.57 58 59.. _fdl-secondary:60 61A "Secondary Section" is a named appendix or a front-matter section of62the :ref:`Document <fdl-document>` that deals exclusively with the63relationship of the publishers or authors of the Document to the64Document's overall subject (or to related matters) and contains nothing65that could fall directly within that overall subject. (For example, if66the Document is in part a textbook of mathematics, a Secondary Section67may not explain any mathematics.) The relationship could be a matter of68historical connection with the subject or with related matters, or of69legal, commercial, philosophical, ethical or political position70regarding them.71 72 73.. _fdl-invariant:74 75The "Invariant Sections" are certain76:ref:`Secondary Sections <fdl-secondary>` whose titles are designated,77as being those of Invariant Sections, in the notice that says that the78:ref:`Document <fdl-document>` is released under this License.79 80 81.. _fdl-cover-texts:82 83The "Cover Texts" are certain short passages of text that are listed, as84Front-Cover Texts or Back-Cover Texts, in the notice that says that the85:ref:`Document <fdl-document>` is released under this License.86 87 88.. _fdl-transparent:89 90A "Transparent" copy of the :ref:`Document <fdl-document>` means a91machine-readable copy, represented in a format whose specification is92available to the general public, whose contents can be viewed and edited93directly and straightforwardly with generic text editors or (for images94composed of pixels) generic paint programs or (for drawings) some widely95available drawing editor, and that is suitable for input to text96formatters or for automatic translation to a variety of formats suitable97for input to text formatters. A copy made in an otherwise Transparent98file format whose markup has been designed to thwart or discourage99subsequent modification by readers is not Transparent. A copy that is100not "Transparent" is called "Opaque".101 102Examples of suitable formats for Transparent copies include plain ASCII103without markup, Texinfo input format, LaTeX input format, SGML or XML104using a publicly available DTD, and standard-conforming simple HTML105designed for human modification. Opaque formats include PostScript, PDF,106proprietary formats that can be read and edited only by proprietary word107processors, SGML or XML for which the DTD and/or processing tools are108not generally available, and the machine-generated HTML produced by some109word processors for output purposes only.110 111 112.. _fdl-title-page:113 114The "Title Page" means, for a printed book, the title page itself, plus115such following pages as are needed to hold, legibly, the material this116License requires to appear in the title page. For works in formats which117do not have any title page as such, "Title Page" means the text near the118most prominent appearance of the work's title, preceding the beginning119of the body of the text.120 121 122.. _fdl-section2:123 1242. VERBATIM COPYING125===================126 127You may copy and distribute the :ref:`Document <fdl-document>` in any128medium, either commercially or noncommercially, provided that this129License, the copyright notices, and the license notice saying this130License applies to the Document are reproduced in all copies, and that131you add no other conditions whatsoever to those of this License. You may132not use technical measures to obstruct or control the reading or further133copying of the copies you make or distribute. However, you may accept134compensation in exchange for copies. If you distribute a large enough135number of copies you must also follow the conditions in136:ref:`section 3 <fdl-section3>`.137 138You may also lend copies, under the same conditions stated above, and139you may publicly display copies.140 141 142.. _fdl-section3:143 1443. COPYING IN QUANTITY145======================146 147If you publish printed copies of the :ref:`Document <fdl-document>`148numbering more than 100, and the Document's license notice requires149:ref:`Cover Texts <fdl-cover-texts>`, you must enclose the copies in150covers that carry, clearly and legibly, all these Cover Texts:151Front-Cover Texts on the front cover, and Back-Cover Texts on the back152cover. Both covers must also clearly and legibly identify you as the153publisher of these copies. The front cover must present the full title154with all words of the title equally prominent and visible. You may add155other material on the covers in addition. Copying with changes limited156to the covers, as long as they preserve the title of the157:ref:`Document <fdl-document>` and satisfy these conditions, can be158treated as verbatim copying in other respects.159 160If the required texts for either cover are too voluminous to fit161legibly, you should put the first ones listed (as many as fit162reasonably) on the actual cover, and continue the rest onto adjacent163pages.164 165If you publish or distribute :ref:`Opaque <fdl-transparent>` copies of166the :ref:`Document <fdl-document>` numbering more than 100, you must167either include a machine-readable :ref:`Transparent <fdl-transparent>`168copy along with each Opaque copy, or state in or with each Opaque copy a169publicly-accessible computer-network location containing a complete170Transparent copy of the Document, free of added material, which the171general network-using public has access to download anonymously at no172charge using public-standard network protocols. If you use the latter173option, you must take reasonably prudent steps, when you begin174distribution of Opaque copies in quantity, to ensure that this175Transparent copy will remain thus accessible at the stated location176until at least one year after the last time you distribute an Opaque177copy (directly or through your agents or retailers) of that edition to178the public.179 180It is requested, but not required, that you contact the authors of the181:ref:`Document <fdl-document>` well before redistributing any large182number of copies, to give them a chance to provide you with an updated183version of the Document.184 185 186.. _fdl-section4:187 1884. MODIFICATIONS189================190 191You may copy and distribute a :ref:`Modified Version <fdl-modified>`192of the :ref:`Document <fdl-document>` under the conditions of sections193:ref:`2 <fdl-section2>` and :ref:`3 <fdl-section3>` above, provided194that you release the Modified Version under precisely this License, with195the Modified Version filling the role of the Document, thus licensing196distribution and modification of the Modified Version to whoever197possesses a copy of it. In addition, you must do these things in the198Modified Version:199 200- **A.**201 Use in the :ref:`Title Page <fdl-title-page>` (and on the covers,202 if any) a title distinct from that of the203 :ref:`Document <fdl-document>`, and from those of previous versions204 (which should, if there were any, be listed in the History section of205 the Document). You may use the same title as a previous version if206 the original publisher of that version gives permission.207 208- **B.**209 List on the :ref:`Title Page <fdl-title-page>`, as authors, one or210 more persons or entities responsible for authorship of the211 modifications in the :ref:`Modified Version <fdl-modified>`,212 together with at least five of the principal authors of the213 :ref:`Document <fdl-document>` (all of its principal authors, if it214 has less than five).215 216- **C.**217 State on the :ref:`Title Page <fdl-title-page>` the name of the218 publisher of the :ref:`Modified Version <fdl-modified>`, as the219 publisher.220 221- **D.**222 Preserve all the copyright notices of the223 :ref:`Document <fdl-document>`.224 225- **E.**226 Add an appropriate copyright notice for your modifications adjacent227 to the other copyright notices.228 229- **F.**230 Include, immediately after the copyright notices, a license notice231 giving the public permission to use the232 :ref:`Modified Version <fdl-modified>` under the terms of this233 License, in the form shown in the Addendum below.234 235- **G.**236 Preserve in that license notice the full lists of237 :ref:`Invariant Sections <fdl-invariant>` and required238 :ref:`Cover Texts <fdl-cover-texts>` given in the239 :ref:`Document's <fdl-document>` license notice.240 241- **H.**242 Include an unaltered copy of this License.243 244- **I.**245 Preserve the section entitled "History", and its title, and add to it246 an item stating at least the title, year, new authors, and publisher247 of the :ref:`Modified Version <fdl-modified>` as given on the248 :ref:`Title Page <fdl-title-page>`. If there is no section entitled249 "History" in the :ref:`Document <fdl-document>`, create one stating250 the title, year, authors, and publisher of the Document as given on251 its Title Page, then add an item describing the Modified Version as252 stated in the previous sentence.253 254- **J.**255 Preserve the network location, if any, given in the256 :ref:`Document <fdl-document>` for public access to a257 :ref:`Transparent <fdl-transparent>` copy of the Document, and258 likewise the network locations given in the Document for previous259 versions it was based on. These may be placed in the "History"260 section. You may omit a network location for a work that was261 published at least four years before the Document itself, or if the262 original publisher of the version it refers to gives permission.263 264- **K.**265 In any section entitled "Acknowledgements" or "Dedications", preserve266 the section's title, and preserve in the section all the substance267 and tone of each of the contributor acknowledgements and/or268 dedications given therein.269 270- **L.**271 Preserve all the :ref:`Invariant Sections <fdl-invariant>` of the272 :ref:`Document <fdl-document>`, unaltered in their text and in273 their titles. Section numbers or the equivalent are not considered274 part of the section titles.275 276- **M.**277 Delete any section entitled "Endorsements". Such a section may not be278 included in the :ref:`Modified Version <fdl-modified>`.279 280- **N.**281 Do not retitle any existing section as "Endorsements" or to conflict282 in title with any :ref:`Invariant Section <fdl-invariant>`.283 284If the :ref:`Modified Version <fdl-modified>` includes new285front-matter sections or appendices that qualify as286:ref:`Secondary Sections <fdl-secondary>` and contain no material287copied from the Document, you may at your option designate some or all288of these sections as invariant. To do this, add their titles to the list289of :ref:`Invariant Sections <fdl-invariant>` in the Modified Version's290license notice. These titles must be distinct from any other section291titles.292 293You may add a section entitled "Endorsements", provided it contains294nothing but endorsements of your295:ref:`Modified Version <fdl-modified>` by various parties--for296example, statements of peer review or that the text has been approved by297an organization as the authoritative definition of a standard.298 299You may add a passage of up to five words as a300:ref:`Front-Cover Text <fdl-cover-texts>`, and a passage of up to 25301words as a :ref:`Back-Cover Text <fdl-cover-texts>`, to the end of the302list of :ref:`Cover Texts <fdl-cover-texts>` in the303:ref:`Modified Version <fdl-modified>`. Only one passage of304Front-Cover Text and one of Back-Cover Text may be added by (or through305arrangements made by) any one entity. If the306:ref:`Document <fdl-document>` already includes a cover text for the307same cover, previously added by you or by arrangement made by the same308entity you are acting on behalf of, you may not add another; but you may309replace the old one, on explicit permission from the previous publisher310that added the old one.311 312The author(s) and publisher(s) of the :ref:`Document <fdl-document>`313do not by this License give permission to use their names for publicity314for or to assert or imply endorsement of any315:ref:`Modified Version <fdl-modified>`.316 317 318.. _fdl-section5:319 3205. COMBINING DOCUMENTS321======================322 323You may combine the :ref:`Document <fdl-document>` with other324documents released under this License, under the terms defined in325:ref:`section 4 <fdl-section4>` above for modified versions, provided326that you include in the combination all of the327:ref:`Invariant Sections <fdl-invariant>` of all of the original328documents, unmodified, and list them all as Invariant Sections of your329combined work in its license notice.330 331The combined work need only contain one copy of this License, and332multiple identical :ref:`Invariant Sections <fdl-invariant>` may be333replaced with a single copy. If there are multiple Invariant Sections334with the same name but different contents, make the title of each such335section unique by adding at the end of it, in parentheses, the name of336the original author or publisher of that section if known, or else a337unique number. Make the same adjustment to the section titles in the338list of Invariant Sections in the license notice of the combined work.339 340In the combination, you must combine any sections entitled "History" in341the various original documents, forming one section entitled "History";342likewise combine any sections entitled "Acknowledgements", and any343sections entitled "Dedications". You must delete all sections entitled344"Endorsements."345 346 347.. _fdl-section6:348 3496. COLLECTIONS OF DOCUMENTS350===========================351 352You may make a collection consisting of the353:ref:`Document <fdl-document>` and other documents released under this354License, and replace the individual copies of this License in the355various documents with a single copy that is included in the collection,356provided that you follow the rules of this License for verbatim copying357of each of the documents in all other respects.358 359You may extract a single document from such a collection, and distribute360it individually under this License, provided you insert a copy of this361License into the extracted document, and follow this License in all362other respects regarding verbatim copying of that document.363 364 365.. _fdl-section7:366 3677. AGGREGATION WITH INDEPENDENT WORKS368=====================================369 370A compilation of the :ref:`Document <fdl-document>` or its derivatives371with other separate and independent documents or works, in or on a372volume of a storage or distribution medium, does not as a whole count as373a :ref:`Modified Version <fdl-modified>` of the Document, provided no374compilation copyright is claimed for the compilation. Such a compilation375is called an "aggregate", and this License does not apply to the other376self-contained works thus compiled with the Document , on account of377their being thus compiled, if they are not themselves derivative works378of the Document. If the :ref:`Cover Text <fdl-cover-texts>`379requirement of :ref:`section 3 <fdl-section3>` is applicable to these380copies of the Document, then if the Document is less than one quarter of381the entire aggregate, the Document's Cover Texts may be placed on covers382that surround only the Document within the aggregate. Otherwise they383must appear on covers around the whole aggregate.384 385 386.. _fdl-section8:387 3888. TRANSLATION389==============390 391Translation is considered a kind of modification, so you may distribute392translations of the :ref:`Document <fdl-document>` under the terms of393:ref:`section 4 <fdl-section4>`. Replacing394:ref:`Invariant Sections <fdl-invariant>` with translations requires395special permission from their copyright holders, but you may include396translations of some or all Invariant Sections in addition to the397original versions of these Invariant Sections. You may include a398translation of this License provided that you also include the original399English version of this License. In case of a disagreement between the400translation and the original English version of this License, the401original English version will prevail.402 403 404.. _fdl-section9:405 4069. TERMINATION407==============408 409You may not copy, modify, sublicense, or distribute the410:ref:`Document <fdl-document>` except as expressly provided for under411this License. Any other attempt to copy, modify, sublicense or412distribute the Document is void, and will automatically terminate your413rights under this License. However, parties who have received copies, or414rights, from you under this License will not have their licenses415terminated so long as such parties remain in full compliance.416 417 418.. _fdl-section10:419 42010. FUTURE REVISIONS OF THIS LICENSE421====================================422 423The `Free Software Foundation <http://www.gnu.org/fsf/fsf.html>`__424may publish new, revised versions of the GNU Free Documentation License425from time to time. Such new versions will be similar in spirit to the426present version, but may differ in detail to address new problems or427concerns. See428`http://www.gnu.org/copyleft/ <http://www.gnu.org/copyleft>`__.429 430Each version of the License is given a distinguishing version number. If431the :ref:`Document <fdl-document>` specifies that a particular432numbered version of this License "or any later version" applies to it,433you have the option of following the terms and conditions either of that434specified version or of any later version that has been published (not435as a draft) by the Free Software Foundation. If the Document does not436specify a version number of this License, you may choose any version437ever published (not as a draft) by the Free Software Foundation.438 439 440.. _fdl-using:441 442Addendum443========444 445To use this License in a document you have written, include a copy of446the License in the document and put the following copyright and license447notices just after the title page:448 449 Copyright © YEAR YOUR NAME.450 451 Permission is granted to copy, distribute and/or modify this452 document under the terms of the GNU Free Documentation License,453 Version 1.1 or any later version published by the Free Software454 Foundation; with the :ref:`Invariant Sections <fdl-invariant>`455 being LIST THEIR TITLES, with the456 :ref:`Front-Cover Texts <fdl-cover-texts>` being LIST, and with457 the :ref:`Back-Cover Texts <fdl-cover-texts>` being LIST. A copy458 of the license is included in the section entitled "GNU Free459 Documentation License".460 461If you have no :ref:`Invariant Sections <fdl-invariant>`, write "with462no Invariant Sections" instead of saying which ones are invariant. If463you have no :ref:`Front-Cover Texts <fdl-cover-texts>`, write "no464Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise465for :ref:`Back-Cover Texts <fdl-cover-texts>`.466 467If your document contains nontrivial examples of program code, we468recommend releasing these examples in parallel under your choice of free469software license, such as the470`GNU General Public License <http://www.gnu.org/copyleft/gpl.html>`__,471to permit their use in free software.472