| .. -*- coding: utf-8; mode: rst -*- | |
| .. _fdl: | |
| ****************************** | |
| GNU Free Documentation License | |
| ****************************** | |
| .. _fdl-preamble: | |
| 0. PREAMBLE | |
| =========== | |
| The purpose of this License is to make a manual, textbook, or other | |
| written document “free” in the sense of freedom: to assure everyone the | |
| effective freedom to copy and redistribute it, with or without modifying | |
| it, either commercially or noncommercially. Secondarily, this License | |
| preserves for the author and publisher a way to get credit for their | |
| work, while not being considered responsible for modifications made by | |
| others. | |
| This License is a kind of “copyleft”, which means that derivative works | |
| of the document must themselves be free in the same sense. It | |
| complements the GNU General Public License, which is a copyleft license | |
| designed for free software. | |
| We have designed this License in order to use it for manuals for free | |
| software, because free software needs free documentation: a free program | |
| should come with manuals providing the same freedoms that the software | |
| does. But this License is not limited to software manuals; it can be | |
| used for any textual work, regardless of subject matter or whether it is | |
| published as a printed book. We recommend this License principally for | |
| works whose purpose is instruction or reference. | |
| .. _fdl-section1: | |
| 1. APPLICABILITY AND DEFINITIONS | |
| ================================ | |
| .. _fdl-document: | |
| This License applies to any manual or other work that contains a notice | |
| placed by the copyright holder saying it can be distributed under the | |
| terms of this License. The “Document”, below, refers to any such manual | |
| or work. Any member of the public is a licensee, and is addressed as | |
| “you”. | |
| .. _fdl-modified: | |
| A “Modified Version” of the Document means any work containing the | |
| Document or a portion of it, either copied verbatim, or with | |
| modifications and/or translated into another language. | |
| .. _fdl-secondary: | |
| A “Secondary Section” is a named appendix or a front-matter section of | |
| the :ref:`Document <fdl-document>` that deals exclusively with the | |
| relationship of the publishers or authors of the Document to the | |
| Document's overall subject (or to related matters) and contains nothing | |
| that could fall directly within that overall subject. (For example, if | |
| the Document is in part a textbook of mathematics, a Secondary Section | |
| may not explain any mathematics.) The relationship could be a matter of | |
| historical connection with the subject or with related matters, or of | |
| legal, commercial, philosophical, ethical or political position | |
| regarding them. | |
| .. _fdl-invariant: | |
| The “Invariant Sections” are certain | |
| :ref:`Secondary Sections <fdl-secondary>` whose titles are designated, | |
| as being those of Invariant Sections, in the notice that says that the | |
| :ref:`Document <fdl-document>` is released under this License. | |
| .. _fdl-cover-texts: | |
| The “Cover Texts” are certain short passages of text that are listed, as | |
| Front-Cover Texts or Back-Cover Texts, in the notice that says that the | |
| :ref:`Document <fdl-document>` is released under this License. | |
| .. _fdl-transparent: | |
| A “Transparent” copy of the :ref:`Document <fdl-document>` means a | |
| machine-readable copy, represented in a format whose specification is | |
| available to the general public, whose contents can be viewed and edited | |
| directly and straightforwardly with generic text editors or (for images | |
| composed of pixels) generic paint programs or (for drawings) some widely | |
| available drawing editor, and that is suitable for input to text | |
| formatters or for automatic translation to a variety of formats suitable | |
| for input to text formatters. A copy made in an otherwise Transparent | |
| file format whose markup has been designed to thwart or discourage | |
| subsequent modification by readers is not Transparent. A copy that is | |
| not “Transparent” is called “Opaque”. | |
| Examples of suitable formats for Transparent copies include plain ASCII | |
| without markup, Texinfo input format, LaTeX input format, SGML or XML | |
| using a publicly available DTD, and standard-conforming simple HTML | |
| designed for human modification. Opaque formats include PostScript, PDF, | |
| proprietary formats that can be read and edited only by proprietary word | |
| processors, SGML or XML for which the DTD and/or processing tools are | |
| not generally available, and the machine-generated HTML produced by some | |
| word processors for output purposes only. | |
| .. _fdl-title-page: | |
| The “Title Page” means, for a printed book, the title page itself, plus | |
| such following pages as are needed to hold, legibly, the material this | |
| License requires to appear in the title page. For works in formats which | |
| do not have any title page as such, “Title Page” means the text near the | |
| most prominent appearance of the work's title, preceding the beginning | |
| of the body of the text. | |
| .. _fdl-section2: | |
| 2. VERBATIM COPYING | |
| =================== | |
| You may copy and distribute the :ref:`Document <fdl-document>` in any | |
| medium, either commercially or noncommercially, provided that this | |
| License, the copyright notices, and the license notice saying this | |
| License applies to the Document are reproduced in all copies, and that | |
| you add no other conditions whatsoever to those of this License. You may | |
| not use technical measures to obstruct or control the reading or further | |
| copying of the copies you make or distribute. However, you may accept | |
| compensation in exchange for copies. If you distribute a large enough | |
| number of copies you must also follow the conditions in | |
| :ref:`section 3 <fdl-section3>`. | |
| You may also lend copies, under the same conditions stated above, and | |
| you may publicly display copies. | |
| .. _fdl-section3: | |
| 3. COPYING IN QUANTITY | |
| ====================== | |
| If you publish printed copies of the :ref:`Document <fdl-document>` | |
| numbering more than 100, and the Document's license notice requires | |
| :ref:`Cover Texts <fdl-cover-texts>`, you must enclose the copies in | |
| covers that carry, clearly and legibly, all these Cover Texts: | |
| Front-Cover Texts on the front cover, and Back-Cover Texts on the back | |
| cover. Both covers must also clearly and legibly identify you as the | |
| publisher of these copies. The front cover must present the full title | |
| with all words of the title equally prominent and visible. You may add | |
| other material on the covers in addition. Copying with changes limited | |
| to the covers, as long as they preserve the title of the | |
| :ref:`Document <fdl-document>` and satisfy these conditions, can be | |
| treated as verbatim copying in other respects. | |
| If the required texts for either cover are too voluminous to fit | |
| legibly, you should put the first ones listed (as many as fit | |
| reasonably) on the actual cover, and continue the rest onto adjacent | |
| pages. | |
| If you publish or distribute :ref:`Opaque <fdl-transparent>` copies of | |
| the :ref:`Document <fdl-document>` numbering more than 100, you must | |
| either include a machine-readable :ref:`Transparent <fdl-transparent>` | |
| copy along with each Opaque copy, or state in or with each Opaque copy a | |
| publicly-accessible computer-network location containing a complete | |
| Transparent copy of the Document, free of added material, which the | |
| general network-using public has access to download anonymously at no | |
| charge using public-standard network protocols. If you use the latter | |
| option, you must take reasonably prudent steps, when you begin | |
| distribution of Opaque copies in quantity, to ensure that this | |
| Transparent copy will remain thus accessible at the stated location | |
| until at least one year after the last time you distribute an Opaque | |
| copy (directly or through your agents or retailers) of that edition to | |
| the public. | |
| It is requested, but not required, that you contact the authors of the | |
| :ref:`Document <fdl-document>` well before redistributing any large | |
| number of copies, to give them a chance to provide you with an updated | |
| version of the Document. | |
| .. _fdl-section4: | |
| 4. MODIFICATIONS | |
| ================ | |
| You may copy and distribute a :ref:`Modified Version <fdl-modified>` | |
| of the :ref:`Document <fdl-document>` under the conditions of sections | |
| :ref:`2 <fdl-section2>` and :ref:`3 <fdl-section3>` above, provided | |
| that you release the Modified Version under precisely this License, with | |
| the Modified Version filling the role of the Document, thus licensing | |
| distribution and modification of the Modified Version to whoever | |
| possesses a copy of it. In addition, you must do these things in the | |
| Modified Version: | |
| - **A.** | |
| Use in the :ref:`Title Page <fdl-title-page>` (and on the covers, | |
| if any) a title distinct from that of the | |
| :ref:`Document <fdl-document>`, and from those of previous versions | |
| (which should, if there were any, be listed in the History section of | |
| the Document). You may use the same title as a previous version if | |
| the original publisher of that version gives permission. | |
| - **B.** | |
| List on the :ref:`Title Page <fdl-title-page>`, as authors, one or | |
| more persons or entities responsible for authorship of the | |
| modifications in the :ref:`Modified Version <fdl-modified>`, | |
| together with at least five of the principal authors of the | |
| :ref:`Document <fdl-document>` (all of its principal authors, if it | |
| has less than five). | |
| - **C.** | |
| State on the :ref:`Title Page <fdl-title-page>` the name of the | |
| publisher of the :ref:`Modified Version <fdl-modified>`, as the | |
| publisher. | |
| - **D.** | |
| Preserve all the copyright notices of the | |
| :ref:`Document <fdl-document>`. | |
| - **E.** | |
| Add an appropriate copyright notice for your modifications adjacent | |
| to the other copyright notices. | |
| - **F.** | |
| Include, immediately after the copyright notices, a license notice | |
| giving the public permission to use the | |
| :ref:`Modified Version <fdl-modified>` under the terms of this | |
| License, in the form shown in the Addendum below. | |
| - **G.** | |
| Preserve in that license notice the full lists of | |
| :ref:`Invariant Sections <fdl-invariant>` and required | |
| :ref:`Cover Texts <fdl-cover-texts>` given in the | |
| :ref:`Document's <fdl-document>` license notice. | |
| - **H.** | |
| Include an unaltered copy of this License. | |
| - **I.** | |
| Preserve the section entitled “History”, and its title, and add to it | |
| an item stating at least the title, year, new authors, and publisher | |
| of the :ref:`Modified Version <fdl-modified>` as given on the | |
| :ref:`Title Page <fdl-title-page>`. If there is no section entitled | |
| “History” in the :ref:`Document <fdl-document>`, create one stating | |
| the title, year, authors, and publisher of the Document as given on | |
| its Title Page, then add an item describing the Modified Version as | |
| stated in the previous sentence. | |
| - **J.** | |
| Preserve the network location, if any, given in the | |
| :ref:`Document <fdl-document>` for public access to a | |
| :ref:`Transparent <fdl-transparent>` copy of the Document, and | |
| likewise the network locations given in the Document for previous | |
| versions it was based on. These may be placed in the “History” | |
| section. You may omit a network location for a work that was | |
| published at least four years before the Document itself, or if the | |
| original publisher of the version it refers to gives permission. | |
| - **K.** | |
| In any section entitled “Acknowledgements” or “Dedications”, preserve | |
| the section's title, and preserve in the section all the substance | |
| and tone of each of the contributor acknowledgements and/or | |
| dedications given therein. | |
| - **L.** | |
| Preserve all the :ref:`Invariant Sections <fdl-invariant>` of the | |
| :ref:`Document <fdl-document>`, unaltered in their text and in | |
| their titles. Section numbers or the equivalent are not considered | |
| part of the section titles. | |
| - **M.** | |
| Delete any section entitled “Endorsements”. Such a section may not be | |
| included in the :ref:`Modified Version <fdl-modified>`. | |
| - **N.** | |
| Do not retitle any existing section as “Endorsements” or to conflict | |
| in title with any :ref:`Invariant Section <fdl-invariant>`. | |
| If the :ref:`Modified Version <fdl-modified>` includes new | |
| front-matter sections or appendices that qualify as | |
| :ref:`Secondary Sections <fdl-secondary>` and contain no material | |
| copied from the Document, you may at your option designate some or all | |
| of these sections as invariant. To do this, add their titles to the list | |
| of :ref:`Invariant Sections <fdl-invariant>` in the Modified Version's | |
| license notice. These titles must be distinct from any other section | |
| titles. | |
| You may add a section entitled “Endorsements”, provided it contains | |
| nothing but endorsements of your | |
| :ref:`Modified Version <fdl-modified>` by various parties--for | |
| example, statements of peer review or that the text has been approved by | |
| an organization as the authoritative definition of a standard. | |
| You may add a passage of up to five words as a | |
| :ref:`Front-Cover Text <fdl-cover-texts>`, and a passage of up to 25 | |
| words as a :ref:`Back-Cover Text <fdl-cover-texts>`, to the end of the | |
| list of :ref:`Cover Texts <fdl-cover-texts>` in the | |
| :ref:`Modified Version <fdl-modified>`. Only one passage of | |
| Front-Cover Text and one of Back-Cover Text may be added by (or through | |
| arrangements made by) any one entity. If the | |
| :ref:`Document <fdl-document>` already includes a cover text for the | |
| same cover, previously added by you or by arrangement made by the same | |
| entity you are acting on behalf of, you may not add another; but you may | |
| replace the old one, on explicit permission from the previous publisher | |
| that added the old one. | |
| The author(s) and publisher(s) of the :ref:`Document <fdl-document>` | |
| do not by this License give permission to use their names for publicity | |
| for or to assert or imply endorsement of any | |
| :ref:`Modified Version <fdl-modified>`. | |
| .. _fdl-section5: | |
| 5. COMBINING DOCUMENTS | |
| ====================== | |
| You may combine the :ref:`Document <fdl-document>` with other | |
| documents released under this License, under the terms defined in | |
| :ref:`section 4 <fdl-section4>` above for modified versions, provided | |
| that you include in the combination all of the | |
| :ref:`Invariant Sections <fdl-invariant>` of all of the original | |
| documents, unmodified, and list them all as Invariant Sections of your | |
| combined work in its license notice. | |
| The combined work need only contain one copy of this License, and | |
| multiple identical :ref:`Invariant Sections <fdl-invariant>` may be | |
| replaced with a single copy. If there are multiple Invariant Sections | |
| with the same name but different contents, make the title of each such | |
| section unique by adding at the end of it, in parentheses, the name of | |
| the original author or publisher of that section if known, or else a | |
| unique number. Make the same adjustment to the section titles in the | |
| list of Invariant Sections in the license notice of the combined work. | |
| In the combination, you must combine any sections entitled “History” in | |
| the various original documents, forming one section entitled “History”; | |
| likewise combine any sections entitled “Acknowledgements”, and any | |
| sections entitled “Dedications”. You must delete all sections entitled | |
| “Endorsements.” | |
| .. _fdl-section6: | |
| 6. COLLECTIONS OF DOCUMENTS | |
| =========================== | |
| You may make a collection consisting of the | |
| :ref:`Document <fdl-document>` and other documents released under this | |
| License, and replace the individual copies of this License in the | |
| various documents with a single copy that is included in the collection, | |
| provided that you follow the rules of this License for verbatim copying | |
| of each of the documents in all other respects. | |
| You may extract a single document from such a collection, and dispbibute | |
| it individually under this License, provided you insert a copy of this | |
| License into the extracted document, and follow this License in all | |
| other respects regarding verbatim copying of that document. | |
| .. _fdl-section7: | |
| 7. AGGREGATION WITH INDEPENDENT WORKS | |
| ===================================== | |
| A compilation of the :ref:`Document <fdl-document>` or its derivatives | |
| with other separate and independent documents or works, in or on a | |
| volume of a storage or distribution medium, does not as a whole count as | |
| a :ref:`Modified Version <fdl-modified>` of the Document, provided no | |
| compilation copyright is claimed for the compilation. Such a compilation | |
| is called an “aggregate”, and this License does not apply to the other | |
| self-contained works thus compiled with the Document , on account of | |
| their being thus compiled, if they are not themselves derivative works | |
| of the Document. If the :ref:`Cover Text <fdl-cover-texts>` | |
| requirement of :ref:`section 3 <fdl-section3>` is applicable to these | |
| copies of the Document, then if the Document is less than one quarter of | |
| the entire aggregate, the Document's Cover Texts may be placed on covers | |
| that surround only the Document within the aggregate. Otherwise they | |
| must appear on covers around the whole aggregate. | |
| .. _fdl-section8: | |
| 8. TRANSLATION | |
| ============== | |
| Translation is considered a kind of modification, so you may distribute | |
| translations of the :ref:`Document <fdl-document>` under the terms of | |
| :ref:`section 4 <fdl-section4>`. Replacing | |
| :ref:`Invariant Sections <fdl-invariant>` with translations requires | |
| special permission from their copyright holders, but you may include | |
| translations of some or all Invariant Sections in addition to the | |
| original versions of these Invariant Sections. You may include a | |
| translation of this License provided that you also include the original | |
| English version of this License. In case of a disagreement between the | |
| translation and the original English version of this License, the | |
| original English version will prevail. | |
| .. _fdl-section9: | |
| 9. TERMINATION | |
| ============== | |
| You may not copy, modify, sublicense, or distribute the | |
| :ref:`Document <fdl-document>` except as expressly provided for under | |
| this License. Any other attempt to copy, modify, sublicense or | |
| distribute the Document is void, and will automatically terminate your | |
| rights under this License. However, parties who have received copies, or | |
| rights, from you under this License will not have their licenses | |
| terminated so long as such parties remain in full compliance. | |
| .. _fdl-section10: | |
| 10. FUTURE REVISIONS OF THIS LICENSE | |
| ==================================== | |
| The `Free Software Foundation <http://www.gnu.org/fsf/fsf.html>`__ | |
| may publish new, revised versions of the GNU Free Documentation License | |
| from time to time. Such new versions will be similar in spirit to the | |
| present version, but may differ in detail to address new problems or | |
| concerns. See | |
| `http://www.gnu.org/copyleft/ <http://www.gnu.org/copyleft>`__. | |
| Each version of the License is given a distinguishing version number. If | |
| the :ref:`Document <fdl-document>` specifies that a particular | |
| numbered version of this License “or any later version” applies to it, | |
| you have the option of following the terms and conditions either of that | |
| specified version or of any later version that has been published (not | |
| as a draft) by the Free Software Foundation. If the Document does not | |
| specify a version number of this License, you may choose any version | |
| ever published (not as a draft) by the Free Software Foundation. | |
| .. _fdl-using: | |
| Addendum | |
| ======== | |
| To use this License in a document you have written, include a copy of | |
| the License in the document and put the following copyright and license | |
| notices just after the title page: | |
| Copyright © YEAR YOUR NAME. | |
| Permission is granted to copy, distribute and/or modify this | |
| document under the terms of the GNU Free Documentation License, | |
| Version 1.1 or any later version published by the Free Software | |
| Foundation; with the :ref:`Invariant Sections <fdl-invariant>` | |
| being LIST THEIR TITLES, with the | |
| :ref:`Front-Cover Texts <fdl-cover-texts>` being LIST, and with | |
| the :ref:`Back-Cover Texts <fdl-cover-texts>` being LIST. A copy | |
| of the license is included in the section entitled “GNU Free | |
| Documentation License”. | |
| If you have no :ref:`Invariant Sections <fdl-invariant>`, write “with | |
| no Invariant Sections” instead of saying which ones are invariant. If | |
| you have no :ref:`Front-Cover Texts <fdl-cover-texts>`, write “no | |
| Front-Cover Texts” instead of “Front-Cover Texts being LIST”; likewise | |
| for :ref:`Back-Cover Texts <fdl-cover-texts>`. | |
| If your document contains nontrivial examples of program code, we | |
| recommend releasing these examples in parallel under your choice of free | |
| software license, such as the | |
| `GNU General Public License <http://www.gnu.org/copyleft/gpl.html>`__, | |
| to permit their use in free software. |