1 GNU Free Documentation License 2 Version 1.2, November 2002 3 4 5 Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 6 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 7 Everyone is permitted to copy and distribute verbatim copies 8 of this license document, but changing it is not allowed. 9 10 110. PREAMBLE 12 13The purpose of this License is to make a manual, textbook, or other 14functional and useful document "free" in the sense of freedom: to 15assure everyone the effective freedom to copy and redistribute it, 16with or without modifying it, either commercially or noncommercially. 17Secondarily, this License preserves for the author and publisher a way 18to get credit for their work, while not being considered responsible 19for modifications made by others. 20 21This License is a kind of "copyleft", which means that derivative 22works of the document must themselves be free in the same sense. It 23complements the GNU General Public License, which is a copyleft 24license designed for free software. 25 26We have designed this License in order to use it for manuals for free 27software, because free software needs free documentation: a free 28program should come with manuals providing the same freedoms that the 29software does. But this License is not limited to software manuals; 30it can be used for any textual work, regardless of subject matter or 31whether it is published as a printed book. We recommend this License 32principally for works whose purpose is instruction or reference. 33 34 351. APPLICABILITY AND DEFINITIONS 36 37This License applies to any manual or other work, in any medium, that 38contains a notice placed by the copyright holder saying it can be 39distributed under the terms of this License. Such a notice grants a 40world-wide, royalty-free license, unlimited in duration, to use that 41work under the conditions stated herein. The "Document", below, 42refers to any such manual or work. Any member of the public is a 43licensee, and is addressed as "you". You accept the license if you 44copy, modify or distribute the work in a way requiring permission 45under copyright law. 46 47A "Modified Version" of the Document means any work containing the 48Document or a portion of it, either copied verbatim, or with 49modifications and/or translated into another language. 50 51A "Secondary Section" is a named appendix or a front-matter section of 52the Document that deals exclusively with the relationship of the 53publishers or authors of the Document to the Document's overall subject 54(or to related matters) and contains nothing that could fall directly 55within that overall subject. (Thus, if the Document is in part a 56textbook of mathematics, a Secondary Section may not explain any 57mathematics.) The relationship could be a matter of historical 58connection with the subject or with related matters, or of legal, 59commercial, philosophical, ethical or political position regarding 60them. 61 62The "Invariant Sections" are certain Secondary Sections whose titles 63are designated, as being those of Invariant Sections, in the notice 64that says that the Document is released under this License. If a 65section does not fit the above definition of Secondary then it is not 66allowed to be designated as Invariant. The Document may contain zero 67Invariant Sections. If the Document does not identify any Invariant 68Sections then there are none. 69 70The "Cover Texts" are certain short passages of text that are listed, 71as Front-Cover Texts or Back-Cover Texts, in the notice that says that 72the Document is released under this License. A Front-Cover Text may 73be at most 5 words, and a Back-Cover Text may be at most 25 words. 74 75A "Transparent" copy of the Document means a machine-readable copy, 76represented in a format whose specification is available to the 77general public, that is suitable for revising the document 78straightforwardly with generic text editors or (for images composed of 79pixels) generic paint programs or (for drawings) some widely available 80drawing editor, and that is suitable for input to text formatters or 81for automatic translation to a variety of formats suitable for input 82to text formatters. A copy made in an otherwise Transparent file 83format whose markup, or absence of markup, has been arranged to thwart 84or discourage subsequent modification by readers is not Transparent. 85An image format is not Transparent if used for any substantial amount 86of text. A copy that is not "Transparent" is called "Opaque". 87 88Examples of suitable formats for Transparent copies include plain 89ASCII without markup, Texinfo input format, LaTeX input format, SGML 90or XML using a publicly available DTD, and standard-conforming simple 91HTML, PostScript or PDF designed for human modification. Examples of 92transparent image formats include PNG, XCF and JPG. Opaque formats 93include proprietary formats that can be read and edited only by 94proprietary word processors, SGML or XML for which the DTD and/or 95processing tools are not generally available, and the 96machine-generated HTML, PostScript or PDF produced by some word 97processors for output purposes only. 98 99The "Title Page" means, for a printed book, the title page itself, 100plus such following pages as are needed to hold, legibly, the material 101this License requires to appear in the title page. For works in 102formats which do not have any title page as such, "Title Page" means 103the text near the most prominent appearance of the work's title, 104preceding the beginning of the body of the text. 105 106A section "Entitled XYZ" means a named subunit of the Document whose 107title either is precisely XYZ or contains XYZ in parentheses following 108text that translates XYZ in another language. (Here XYZ stands for a 109specific section name mentioned below, such as "Acknowledgements", 110"Dedications", "Endorsements", or "History".) To "Preserve the Title" 111of such a section when you modify the Document means that it remains a 112section "Entitled XYZ" according to this definition. 113 114The Document may include Warranty Disclaimers next to the notice which 115states that this License applies to the Document. These Warranty 116Disclaimers are considered to be included by reference in this 117License, but only as regards disclaiming warranties: any other 118implication that these Warranty Disclaimers may have is void and has 119no effect on the meaning of this License. 120 121 1222. VERBATIM COPYING 123 124You may copy and distribute the Document in any medium, either 125commercially or noncommercially, provided that this License, the 126copyright notices, and the license notice saying this License applies 127to the Document are reproduced in all copies, and that you add no other 128conditions whatsoever to those of this License. You may not use 129technical measures to obstruct or control the reading or further 130copying of the copies you make or distribute. However, you may accept 131compensation in exchange for copies. If you distribute a large enough 132number of copies you must also follow the conditions in section 3. 133 134You may also lend copies, under the same conditions stated above, and 135you may publicly display copies. 136 137 1383. COPYING IN QUANTITY 139 140If you publish printed copies (or copies in media that commonly have 141printed covers) of the Document, numbering more than 100, and the 142Document's license notice requires Cover Texts, you must enclose the 143copies in covers that carry, clearly and legibly, all these Cover 144Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on 145the back cover. Both covers must also clearly and legibly identify 146you as the publisher of these copies. The front cover must present 147the full title with all words of the title equally prominent and 148visible. You may add other material on the covers in addition. 149Copying with changes limited to the covers, as long as they preserve 150the title of the Document and satisfy these conditions, can be treated 151as verbatim copying in other respects. 152 153If the required texts for either cover are too voluminous to fit 154legibly, you should put the first ones listed (as many as fit 155reasonably) on the actual cover, and continue the rest onto adjacent 156pages. 157 158If you publish or distribute Opaque copies of the Document numbering 159more than 100, you must either include a machine-readable Transparent 160copy along with each Opaque copy, or state in or with each Opaque copy 161a computer-network location from which the general network-using 162public has access to download using public-standard network protocols 163a complete Transparent copy of the Document, free of added material. 164If you use the latter option, you must take reasonably prudent steps, 165when you begin distribution of Opaque copies in quantity, to ensure 166that this Transparent copy will remain thus accessible at the stated 167location until at least one year after the last time you distribute an 168Opaque copy (directly or through your agents or retailers) of that 169edition to the public. 170 171It is requested, but not required, that you contact the authors of the 172Document well before redistributing any large number of copies, to give 173them a chance to provide you with an updated version of the Document. 174 175 1764. MODIFICATIONS 177 178You may copy and distribute a Modified Version of the Document under 179the conditions of sections 2 and 3 above, provided that you release 180the Modified Version under precisely this License, with the Modified 181Version filling the role of the Document, thus licensing distribution 182and modification of the Modified Version to whoever possesses a copy 183of it. In addition, you must do these things in the Modified Version: 184 185A. Use in the Title Page (and on the covers, if any) a title distinct 186 from that of the Document, and from those of previous versions 187 (which should, if there were any, be listed in the History section 188 of the Document). You may use the same title as a previous version 189 if the original publisher of that version gives permission. 190B. List on the Title Page, as authors, one or more persons or entities 191 responsible for authorship of the modifications in the Modified 192 Version, together with at least five of the principal authors of the 193 Document (all of its principal authors, if it has fewer than five), 194 unless they release you from this requirement. 195C. State on the Title page the name of the publisher of the 196 Modified Version, as the publisher. 197D. Preserve all the copyright notices of the Document. 198E. Add an appropriate copyright notice for your modifications 199 adjacent to the other copyright notices. 200F. Include, immediately after the copyright notices, a license notice 201 giving the public permission to use the Modified Version under the 202 terms of this License, in the form shown in the Addendum below. 203G. Preserve in that license notice the full lists of Invariant Sections 204 and required Cover Texts given in the Document's license notice. 205H. Include an unaltered copy of this License. 206I. Preserve the section Entitled "History", Preserve its Title, and add 207 to it an item stating at least the title, year, new authors, and 208 publisher of the Modified Version as given on the Title Page. If 209 there is no section Entitled "History" in the Document, create one 210 stating the title, year, authors, and publisher of the Document as 211 given on its Title Page, then add an item describing the Modified 212 Version as stated in the previous sentence. 213J. Preserve the network location, if any, given in the Document for 214 public access to a Transparent copy of the Document, and likewise 215 the network locations given in the Document for previous versions 216 it was based on. These may be placed in the "History" section. 217 You may omit a network location for a work that was published at 218 least four years before the Document itself, or if the original 219 publisher of the version it refers to gives permission. 220K. For any section Entitled "Acknowledgements" or "Dedications", 221 Preserve the Title of the section, and preserve in the section all 222 the substance and tone of each of the contributor acknowledgements 223 and/or dedications given therein. 224L. Preserve all the Invariant Sections of the Document, 225 unaltered in their text and in their titles. Section numbers 226 or the equivalent are not considered part of the section titles. 227M. Delete any section Entitled "Endorsements". Such a section 228 may not be included in the Modified Version. 229N. Do not retitle any existing section to be Entitled "Endorsements" 230 or to conflict in title with any Invariant Section. 231O. Preserve any Warranty Disclaimers. 232 233If the Modified Version includes new front-matter sections or 234appendices that qualify as Secondary Sections and contain no material 235copied from the Document, you may at your option designate some or all 236of these sections as invariant. To do this, add their titles to the 237list of Invariant Sections in the Modified Version's license notice. 238These titles must be distinct from any other section titles. 239 240You may add a section Entitled "Endorsements", provided it contains 241nothing but endorsements of your Modified Version by various 242parties--for example, statements of peer review or that the text has 243been approved by an organization as the authoritative definition of a 244standard. 245 246You may add a passage of up to five words as a Front-Cover Text, and a 247passage of up to 25 words as a Back-Cover Text, to the end of the list 248of Cover Texts in the Modified Version. Only one passage of 249Front-Cover Text and one of Back-Cover Text may be added by (or 250through arrangements made by) any one entity. If the Document already 251includes a cover text for the same cover, previously added by you or 252by arrangement made by the same entity you are acting on behalf of, 253you may not add another; but you may replace the old one, on explicit 254permission from the previous publisher that added the old one. 255 256The author(s) and publisher(s) of the Document do not by this License 257give permission to use their names for publicity for or to assert or 258imply endorsement of any Modified Version. 259 260 2615. COMBINING DOCUMENTS 262 263You may combine the Document with other documents released under this 264License, under the terms defined in section 4 above for modified 265versions, provided that you include in the combination all of the 266Invariant Sections of all of the original documents, unmodified, and 267list them all as Invariant Sections of your combined work in its 268license notice, and that you preserve all their Warranty Disclaimers. 269 270The combined work need only contain one copy of this License, and 271multiple identical Invariant Sections may be replaced with a single 272copy. If there are multiple Invariant Sections with the same name but 273different contents, make the title of each such section unique by 274adding at the end of it, in parentheses, the name of the original 275author or publisher of that section if known, or else a unique number. 276Make the same adjustment to the section titles in the list of 277Invariant Sections in the license notice of the combined work. 278 279In the combination, you must combine any sections Entitled "History" 280in the various original documents, forming one section Entitled 281"History"; likewise combine any sections Entitled "Acknowledgements", 282and any sections Entitled "Dedications". You must delete all sections 283Entitled "Endorsements". 284 285 2866. COLLECTIONS OF DOCUMENTS 287 288You may make a collection consisting of the Document and other documents 289released under this License, and replace the individual copies of this 290License in the various documents with a single copy that is included in 291the collection, provided that you follow the rules of this License for 292verbatim copying of each of the documents in all other respects. 293 294You may extract a single document from such a collection, and distribute 295it individually under this License, provided you insert a copy of this 296License into the extracted document, and follow this License in all 297other respects regarding verbatim copying of that document. 298 299 3007. AGGREGATION WITH INDEPENDENT WORKS 301 302A compilation of the Document or its derivatives with other separate 303and independent documents or works, in or on a volume of a storage or 304distribution medium, is called an "aggregate" if the copyright 305resulting from the compilation is not used to limit the legal rights 306of the compilation's users beyond what the individual works permit. 307When the Document is included in an aggregate, this License does not 308apply to the other works in the aggregate which are not themselves 309derivative works of the Document. 310 311If the Cover Text requirement of section 3 is applicable to these 312copies of the Document, then if the Document is less than one half of 313the entire aggregate, the Document's Cover Texts may be placed on 314covers that bracket the Document within the aggregate, or the 315electronic equivalent of covers if the Document is in electronic form. 316Otherwise they must appear on printed covers that bracket the whole 317aggregate. 318 319 3208. TRANSLATION 321 322Translation is considered a kind of modification, so you may 323distribute translations of the Document under the terms of section 4. 324Replacing Invariant Sections with translations requires special 325permission from their copyright holders, but you may include 326translations of some or all Invariant Sections in addition to the 327original versions of these Invariant Sections. You may include a 328translation of this License, and all the license notices in the 329Document, and any Warranty Disclaimers, provided that you also include 330the original English version of this License and the original versions 331of those notices and disclaimers. In case of a disagreement between 332the translation and the original version of this License or a notice 333or disclaimer, the original version will prevail. 334 335If a section in the Document is Entitled "Acknowledgements", 336"Dedications", or "History", the requirement (section 4) to Preserve 337its Title (section 1) will typically require changing the actual 338title. 339 340 3419. TERMINATION 342 343You may not copy, modify, sublicense, or distribute the Document except 344as expressly provided for under this License. Any other attempt to 345copy, modify, sublicense or distribute the Document is void, and will 346automatically terminate your rights under this License. However, 347parties who have received copies, or rights, from you under this 348License will not have their licenses terminated so long as such 349parties remain in full compliance. 350 351 35210. FUTURE REVISIONS OF THIS LICENSE 353 354The Free Software Foundation may publish new, revised versions 355of the GNU Free Documentation License from time to time. Such new 356versions will be similar in spirit to the present version, but may 357differ in detail to address new problems or concerns. See 358http://www.gnu.org/copyleft/. 359 360Each version of the License is given a distinguishing version number. 361If the Document specifies that a particular numbered version of this 362License "or any later version" applies to it, you have the option of 363following the terms and conditions either of that specified version or 364of any later version that has been published (not as a draft) by the 365Free Software Foundation. If the Document does not specify a version 366number of this License, you may choose any version ever published (not 367as a draft) by the Free Software Foundation. 368 369 370ADDENDUM: How to use this License for your documents 371 372To use this License in a document you have written, include a copy of 373the License in the document and put the following copyright and 374license notices just after the title page: 375 376 Copyright (c) YEAR YOUR NAME. 377 Permission is granted to copy, distribute and/or modify this document 378 under the terms of the GNU Free Documentation License, Version 1.2 379 or any later version published by the Free Software Foundation; 380 with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. 381 A copy of the license is included in the section entitled "GNU 382 Free Documentation License". 383 384If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, 385replace the "with...Texts." line with this: 386 387 with the Invariant Sections being LIST THEIR TITLES, with the 388 Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. 389 390If you have Invariant Sections without Cover Texts, or some other 391combination of the three, merge those two alternatives to suit the 392situation. 393 394If your document contains nontrivial examples of program code, we 395recommend releasing these examples in parallel under your choice of 396free software license, such as the GNU General Public License, 397to permit their use in free software. 398 399