1.. Permission is granted to copy, distribute and/or modify this 2.. document under the terms of the GNU Free Documentation License, 3.. Version 1.1 or any later version published by the Free Software 4.. Foundation, with no Invariant Sections, no Front-Cover Texts 5.. and no Back-Cover Texts. A copy of the license is included at 6.. Documentation/userspace-api/media/fdl-appendix.rst. 7.. 8.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections 9 10.. _fdl: 11 12****************************** 13GNU Free Documentation License 14****************************** 15 16 17.. _fdl-preamble: 18 190. PREAMBLE 20=========== 21 22The purpose of this License is to make a manual, textbook, or other 23written document “free” in the sense of freedom: to assure everyone the 24effective freedom to copy and redistribute it, with or without modifying 25it, either commercially or noncommercially. Secondarily, this License 26preserves for the author and publisher a way to get credit for their 27work, while not being considered responsible for modifications made by 28others. 29 30This License is a kind of “copyleft”, which means that derivative works 31of the document must themselves be free in the same sense. It 32complements the GNU General Public License, which is a copyleft license 33designed for free software. 34 35We have designed this License in order to use it for manuals for free 36software, because free software needs free documentation: a free program 37should come with manuals providing the same freedoms that the software 38does. But this License is not limited to software manuals; it can be 39used for any textual work, regardless of subject matter or whether it is 40published as a printed book. We recommend this License principally for 41works whose purpose is instruction or reference. 42 43 44.. _fdl-section1: 45 461. APPLICABILITY AND DEFINITIONS 47================================ 48 49 50.. _fdl-document: 51 52This License applies to any manual or other work that contains a notice 53placed by the copyright holder saying it can be distributed under the 54terms of this License. The “Document”, below, refers to any such manual 55or work. Any member of the public is a licensee, and is addressed as 56“you”. 57 58 59.. _fdl-modified: 60 61A “Modified Version” of the Document means any work containing the 62Document or a portion of it, either copied verbatim, or with 63modifications and/or translated into another language. 64 65 66.. _fdl-secondary: 67 68A “Secondary Section” is a named appendix or a front-matter section of 69the :ref:`Document <fdl-document>` that deals exclusively with the 70relationship of the publishers or authors of the Document to the 71Document's overall subject (or to related matters) and contains nothing 72that could fall directly within that overall subject. (For example, if 73the Document is in part a textbook of mathematics, a Secondary Section 74may not explain any mathematics.) The relationship could be a matter of 75historical connection with the subject or with related matters, or of 76legal, commercial, philosophical, ethical or political position 77regarding them. 78 79 80.. _fdl-invariant: 81 82The “Invariant Sections” are certain 83:ref:`Secondary Sections <fdl-secondary>` whose titles are designated, 84as being those of Invariant Sections, in the notice that says that the 85:ref:`Document <fdl-document>` is released under this License. 86 87 88.. _fdl-cover-texts: 89 90The “Cover Texts” are certain short passages of text that are listed, as 91Front-Cover Texts or Back-Cover Texts, in the notice that says that the 92:ref:`Document <fdl-document>` is released under this License. 93 94 95.. _fdl-transparent: 96 97A “Transparent” copy of the :ref:`Document <fdl-document>` means a 98machine-readable copy, represented in a format whose specification is 99available to the general public, whose contents can be viewed and edited 100directly and straightforwardly with generic text editors or (for images 101composed of pixels) generic paint programs or (for drawings) some widely 102available drawing editor, and that is suitable for input to text 103formatters or for automatic translation to a variety of formats suitable 104for input to text formatters. A copy made in an otherwise Transparent 105file format whose markup has been designed to thwart or discourage 106subsequent modification by readers is not Transparent. A copy that is 107not “Transparent” is called “Opaque”. 108 109Examples of suitable formats for Transparent copies include plain ASCII 110without markup, Texinfo input format, LaTeX input format, SGML or XML 111using a publicly available DTD, and standard-conforming simple HTML 112designed for human modification. Opaque formats include PostScript, PDF, 113proprietary formats that can be read and edited only by proprietary word 114processors, SGML or XML for which the DTD and/or processing tools are 115not generally available, and the machine-generated HTML produced by some 116word processors for output purposes only. 117 118 119.. _fdl-title-page: 120 121The “Title Page” means, for a printed book, the title page itself, plus 122such following pages as are needed to hold, legibly, the material this 123License requires to appear in the title page. For works in formats which 124do not have any title page as such, “Title Page” means the text near the 125most prominent appearance of the work's title, preceding the beginning 126of the body of the text. 127 128 129.. _fdl-section2: 130 1312. VERBATIM COPYING 132=================== 133 134You may copy and distribute the :ref:`Document <fdl-document>` in any 135medium, either commercially or noncommercially, provided that this 136License, the copyright notices, and the license notice saying this 137License applies to the Document are reproduced in all copies, and that 138you add no other conditions whatsoever to those of this License. You may 139not use technical measures to obstruct or control the reading or further 140copying of the copies you make or distribute. However, you may accept 141compensation in exchange for copies. If you distribute a large enough 142number of copies you must also follow the conditions in 143:ref:`section 3 <fdl-section3>`. 144 145You may also lend copies, under the same conditions stated above, and 146you may publicly display copies. 147 148 149.. _fdl-section3: 150 1513. COPYING IN QUANTITY 152====================== 153 154If you publish printed copies of the :ref:`Document <fdl-document>` 155numbering more than 100, and the Document's license notice requires 156:ref:`Cover Texts <fdl-cover-texts>`, you must enclose the copies in 157covers that carry, clearly and legibly, all these Cover Texts: 158Front-Cover Texts on the front cover, and Back-Cover Texts on the back 159cover. Both covers must also clearly and legibly identify you as the 160publisher of these copies. The front cover must present the full title 161with all words of the title equally prominent and visible. You may add 162other material on the covers in addition. Copying with changes limited 163to the covers, as long as they preserve the title of the 164:ref:`Document <fdl-document>` and satisfy these conditions, can be 165treated as verbatim copying in other respects. 166 167If the required texts for either cover are too voluminous to fit 168legibly, you should put the first ones listed (as many as fit 169reasonably) on the actual cover, and continue the rest onto adjacent 170pages. 171 172If you publish or distribute :ref:`Opaque <fdl-transparent>` copies of 173the :ref:`Document <fdl-document>` numbering more than 100, you must 174either include a machine-readable :ref:`Transparent <fdl-transparent>` 175copy along with each Opaque copy, or state in or with each Opaque copy a 176publicly-accessible computer-network location containing a complete 177Transparent copy of the Document, free of added material, which the 178general network-using public has access to download anonymously at no 179charge using public-standard network protocols. If you use the latter 180option, you must take reasonably prudent steps, when you begin 181distribution of Opaque copies in quantity, to ensure that this 182Transparent copy will remain thus accessible at the stated location 183until at least one year after the last time you distribute an Opaque 184copy (directly or through your agents or retailers) of that edition to 185the public. 186 187It is requested, but not required, that you contact the authors of the 188:ref:`Document <fdl-document>` well before redistributing any large 189number of copies, to give them a chance to provide you with an updated 190version of the Document. 191 192 193.. _fdl-section4: 194 1954. MODIFICATIONS 196================ 197 198You may copy and distribute a :ref:`Modified Version <fdl-modified>` 199of the :ref:`Document <fdl-document>` under the conditions of sections 200:ref:`2 <fdl-section2>` and :ref:`3 <fdl-section3>` above, provided 201that you release the Modified Version under precisely this License, with 202the Modified Version filling the role of the Document, thus licensing 203distribution and modification of the Modified Version to whoever 204possesses a copy of it. In addition, you must do these things in the 205Modified Version: 206 207- **A.** 208 Use in the :ref:`Title Page <fdl-title-page>` (and on the covers, 209 if any) a title distinct from that of the 210 :ref:`Document <fdl-document>`, and from those of previous versions 211 (which should, if there were any, be listed in the History section of 212 the Document). You may use the same title as a previous version if 213 the original publisher of that version gives permission. 214 215- **B.** 216 List on the :ref:`Title Page <fdl-title-page>`, as authors, one or 217 more persons or entities responsible for authorship of the 218 modifications in the :ref:`Modified Version <fdl-modified>`, 219 together with at least five of the principal authors of the 220 :ref:`Document <fdl-document>` (all of its principal authors, if it 221 has less than five). 222 223- **C.** 224 State on the :ref:`Title Page <fdl-title-page>` the name of the 225 publisher of the :ref:`Modified Version <fdl-modified>`, as the 226 publisher. 227 228- **D.** 229 Preserve all the copyright notices of the 230 :ref:`Document <fdl-document>`. 231 232- **E.** 233 Add an appropriate copyright notice for your modifications adjacent 234 to the other copyright notices. 235 236- **F.** 237 Include, immediately after the copyright notices, a license notice 238 giving the public permission to use the 239 :ref:`Modified Version <fdl-modified>` under the terms of this 240 License, in the form shown in the Addendum below. 241 242- **G.** 243 Preserve in that license notice the full lists of 244 :ref:`Invariant Sections <fdl-invariant>` and required 245 :ref:`Cover Texts <fdl-cover-texts>` given in the 246 :ref:`Document's <fdl-document>` license notice. 247 248- **H.** 249 Include an unaltered copy of this License. 250 251- **I.** 252 Preserve the section entitled “History”, and its title, and add to it 253 an item stating at least the title, year, new authors, and publisher 254 of the :ref:`Modified Version <fdl-modified>` as given on the 255 :ref:`Title Page <fdl-title-page>`. If there is no section entitled 256 “History” in the :ref:`Document <fdl-document>`, create one stating 257 the title, year, authors, and publisher of the Document as given on 258 its Title Page, then add an item describing the Modified Version as 259 stated in the previous sentence. 260 261- **J.** 262 Preserve the network location, if any, given in the 263 :ref:`Document <fdl-document>` for public access to a 264 :ref:`Transparent <fdl-transparent>` copy of the Document, and 265 likewise the network locations given in the Document for previous 266 versions it was based on. These may be placed in the “History” 267 section. You may omit a network location for a work that was 268 published at least four years before the Document itself, or if the 269 original publisher of the version it refers to gives permission. 270 271- **K.** 272 In any section entitled “Acknowledgements” or “Dedications”, preserve 273 the section's title, and preserve in the section all the substance 274 and tone of each of the contributor acknowledgements and/or 275 dedications given therein. 276 277- **L.** 278 Preserve all the :ref:`Invariant Sections <fdl-invariant>` of the 279 :ref:`Document <fdl-document>`, unaltered in their text and in 280 their titles. Section numbers or the equivalent are not considered 281 part of the section titles. 282 283- **M.** 284 Delete any section entitled “Endorsements”. Such a section may not be 285 included in the :ref:`Modified Version <fdl-modified>`. 286 287- **N.** 288 Do not retitle any existing section as “Endorsements” or to conflict 289 in title with any :ref:`Invariant Section <fdl-invariant>`. 290 291If the :ref:`Modified Version <fdl-modified>` includes new 292front-matter sections or appendices that qualify as 293:ref:`Secondary Sections <fdl-secondary>` and contain no material 294copied from the Document, you may at your option designate some or all 295of these sections as invariant. To do this, add their titles to the list 296of :ref:`Invariant Sections <fdl-invariant>` in the Modified Version's 297license notice. These titles must be distinct from any other section 298titles. 299 300You may add a section entitled “Endorsements”, provided it contains 301nothing but endorsements of your 302:ref:`Modified Version <fdl-modified>` by various parties--for 303example, statements of peer review or that the text has been approved by 304an organization as the authoritative definition of a standard. 305 306You may add a passage of up to five words as a 307:ref:`Front-Cover Text <fdl-cover-texts>`, and a passage of up to 25 308words as a :ref:`Back-Cover Text <fdl-cover-texts>`, to the end of the 309list of :ref:`Cover Texts <fdl-cover-texts>` in the 310:ref:`Modified Version <fdl-modified>`. Only one passage of 311Front-Cover Text and one of Back-Cover Text may be added by (or through 312arrangements made by) any one entity. If the 313:ref:`Document <fdl-document>` already includes a cover text for the 314same cover, previously added by you or by arrangement made by the same 315entity you are acting on behalf of, you may not add another; but you may 316replace the old one, on explicit permission from the previous publisher 317that added the old one. 318 319The author(s) and publisher(s) of the :ref:`Document <fdl-document>` 320do not by this License give permission to use their names for publicity 321for or to assert or imply endorsement of any 322:ref:`Modified Version <fdl-modified>`. 323 324 325.. _fdl-section5: 326 3275. COMBINING DOCUMENTS 328====================== 329 330You may combine the :ref:`Document <fdl-document>` with other 331documents released under this License, under the terms defined in 332:ref:`section 4 <fdl-section4>` above for modified versions, provided 333that you include in the combination all of the 334:ref:`Invariant Sections <fdl-invariant>` of all of the original 335documents, unmodified, and list them all as Invariant Sections of your 336combined work in its license notice. 337 338The combined work need only contain one copy of this License, and 339multiple identical :ref:`Invariant Sections <fdl-invariant>` may be 340replaced with a single copy. If there are multiple Invariant Sections 341with the same name but different contents, make the title of each such 342section unique by adding at the end of it, in parentheses, the name of 343the original author or publisher of that section if known, or else a 344unique number. Make the same adjustment to the section titles in the 345list of Invariant Sections in the license notice of the combined work. 346 347In the combination, you must combine any sections entitled “History” in 348the various original documents, forming one section entitled “History”; 349likewise combine any sections entitled “Acknowledgements”, and any 350sections entitled “Dedications”. You must delete all sections entitled 351“Endorsements.” 352 353 354.. _fdl-section6: 355 3566. COLLECTIONS OF DOCUMENTS 357=========================== 358 359You may make a collection consisting of the 360:ref:`Document <fdl-document>` and other documents released under this 361License, and replace the individual copies of this License in the 362various documents with a single copy that is included in the collection, 363provided that you follow the rules of this License for verbatim copying 364of each of the documents in all other respects. 365 366You may extract a single document from such a collection, and distribute 367it individually under this License, provided you insert a copy of this 368License into the extracted document, and follow this License in all 369other respects regarding verbatim copying of that document. 370 371 372.. _fdl-section7: 373 3747. AGGREGATION WITH INDEPENDENT WORKS 375===================================== 376 377A compilation of the :ref:`Document <fdl-document>` or its derivatives 378with other separate and independent documents or works, in or on a 379volume of a storage or distribution medium, does not as a whole count as 380a :ref:`Modified Version <fdl-modified>` of the Document, provided no 381compilation copyright is claimed for the compilation. Such a compilation 382is called an “aggregate”, and this License does not apply to the other 383self-contained works thus compiled with the Document , on account of 384their being thus compiled, if they are not themselves derivative works 385of the Document. If the :ref:`Cover Text <fdl-cover-texts>` 386requirement of :ref:`section 3 <fdl-section3>` is applicable to these 387copies of the Document, then if the Document is less than one quarter of 388the entire aggregate, the Document's Cover Texts may be placed on covers 389that surround only the Document within the aggregate. Otherwise they 390must appear on covers around the whole aggregate. 391 392 393.. _fdl-section8: 394 3958. TRANSLATION 396============== 397 398Translation is considered a kind of modification, so you may distribute 399translations of the :ref:`Document <fdl-document>` under the terms of 400:ref:`section 4 <fdl-section4>`. Replacing 401:ref:`Invariant Sections <fdl-invariant>` with translations requires 402special permission from their copyright holders, but you may include 403translations of some or all Invariant Sections in addition to the 404original versions of these Invariant Sections. You may include a 405translation of this License provided that you also include the original 406English version of this License. In case of a disagreement between the 407translation and the original English version of this License, the 408original English version will prevail. 409 410 411.. _fdl-section9: 412 4139. TERMINATION 414============== 415 416You may not copy, modify, sublicense, or distribute the 417:ref:`Document <fdl-document>` except as expressly provided for under 418this License. Any other attempt to copy, modify, sublicense or 419distribute the Document is void, and will automatically terminate your 420rights under this License. However, parties who have received copies, or 421rights, from you under this License will not have their licenses 422terminated so long as such parties remain in full compliance. 423 424 425.. _fdl-section10: 426 42710. FUTURE REVISIONS OF THIS LICENSE 428==================================== 429 430The `Free Software Foundation <http://www.gnu.org/fsf/fsf.html>`__ 431may publish new, revised versions of the GNU Free Documentation License 432from time to time. Such new versions will be similar in spirit to the 433present version, but may differ in detail to address new problems or 434concerns. See 435`http://www.gnu.org/copyleft/ <http://www.gnu.org/copyleft>`__. 436 437Each version of the License is given a distinguishing version number. If 438the :ref:`Document <fdl-document>` specifies that a particular 439numbered version of this License “or any later version” applies to it, 440you have the option of following the terms and conditions either of that 441specified version or of any later version that has been published (not 442as a draft) by the Free Software Foundation. If the Document does not 443specify a version number of this License, you may choose any version 444ever published (not as a draft) by the Free Software Foundation. 445 446 447.. _fdl-using: 448 449Addendum 450======== 451 452To use this License in a document you have written, include a copy of 453the License in the document and put the following copyright and license 454notices just after the title page: 455 456 Copyright © YEAR YOUR NAME. 457 458 Permission is granted to copy, distribute and/or modify this 459 document under the terms of the GNU Free Documentation License, 460 Version 1.1 or any later version published by the Free Software 461 Foundation; with the :ref:`Invariant Sections <fdl-invariant>` 462 being LIST THEIR TITLES, with the 463 :ref:`Front-Cover Texts <fdl-cover-texts>` being LIST, and with 464 the :ref:`Back-Cover Texts <fdl-cover-texts>` being LIST. A copy 465 of the license is included in the section entitled “GNU Free 466 Documentation License”. 467 468If you have no :ref:`Invariant Sections <fdl-invariant>`, write “with 469no Invariant Sections” instead of saying which ones are invariant. If 470you have no :ref:`Front-Cover Texts <fdl-cover-texts>`, write “no 471Front-Cover Texts” instead of “Front-Cover Texts being LIST”; likewise 472for :ref:`Back-Cover Texts <fdl-cover-texts>`. 473 474If your document contains nontrivial examples of program code, we 475recommend releasing these examples in parallel under your choice of free 476software license, such as the 477`GNU General Public License <http://www.gnu.org/copyleft/gpl.html>`__, 478to permit their use in free software. 479