Appendix A. GNU Free Documentation License 259The Free Software Foundation may publish new, revised versions of the GNU Free Documenta-tion 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/.Each version of the License is given a distinguishing version number. If the Document speci-fies that a particular numbered version of this License "or any later version" applies to it, youhave the option of following the terms and conditions either of that specified version or of anylater version that has been published (not as a draft) by the Free Software Foundation. If theDocument does not specify a version number of this License, you may choose any version everpublished (not as a draft) by the Free Software Foundation.A.1. ADDENDUM: How to use this License for your documentsTo use this License in a document you have written, include a copy of the License in the documentand put the following copyright and license notices just after the title page:Copyright (C) year your name.Permission is granted to copy, distribute and/or modify this documentunder the terms of the GNU Free Documentation License, Version 1.1or any later version published by the Free Software Foundation;with the Invariant Sections being list their titles, with theFront-Cover Texts being list, and with the Back-Cover Texts being list.A copy of the license is included in the section entitled "GNUFree Documentation License."If you have no Invariant Sections, write "with no Invariant Sections" instead of saying which onesare invariant. If you have no Front-Cover Texts, write "no Front-Cover Texts" instead of "Front-CoverTexts being list"; likewise for Back-Cover Texts.If your document contains nontrivial examples of program code, we recommend releasing these exam-ples in parallel under your choice of free software license, such as the GNU General Public License,to permit their use in free software.