com/options/license/GFDL-1.1-or-later

GNU Free Documentation License

Version 1.1, March 2000

Copyright (C) 2000 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor,
Boston, MA 02110-1301 USA

Everyone is permitted to copy and distribute verbatim copies of this license
document, but changing it is not allowed.

   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.

   1. APPLICABILITY AND DEFINITIONS

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".

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.

A "Secondary Section" is a named appendix or a front-matter section of the
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.

The "Invariant Sections" are certain Secondary Sections whose titles are designated,
as being those of Invariant Sections, in the notice that says that the Document
is released under this License.

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 Document is released
under this License.

A "Transparent" copy of the 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.

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.

   2. VERBATIM COPYING

You may copy and distribute the 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 section 3.

You may also lend copies, under the same conditions stated above, and you
may publicly display copies.

   3. COPYING IN QUANTITY

If you publish printed copies of the Document numbering more than 100, and
the Document's license notice requires 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 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 Opaque copies of the Document numbering more
than 100, you must either include a machine-readable 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 Document
well before redistributing any large number of copies, to give them a chance
to provide you with an updated version of the Document.

   4. MODIFICATIONS

You may copy and distribute a Modified Version of the Document under the conditions
of sections 2 and 3 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 Title Page (and on the covers, if any) a title distinct from
that of the 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 Title Page, as authors, one or more persons or entities responsible
for authorship of the modifications in the Modified Version, together with
at least five of the principal authors of the Document (all of its principal
authors, if it has less than five).

C. State on the Title page the name of the publisher of the Modified Version,
as the publisher.

      D. Preserve all the copyright notices of the 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 Modified Version under the terms of this
License, in the form shown in the Addendum below.

G. Preserve in that license notice the full lists of Invariant Sections and
required Cover Texts given in the Document's 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 Modified
Version as given on the Title Page. If there is no section entitled "History"
in the 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 Document for public
access to a 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 Invariant Sections of the 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 Modified Version.

N. Do not retitle any existing section as "Endorsements" or to conflict in
title with any Invariant Section.

If the Modified Version includes new front-matter sections or appendices that
qualify as Secondary Sections 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 Invariant Sections 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 Modified Version 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 Front-Cover Text, and a passage
of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts
in the Modified Version. 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 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 Document do not by this License give
permission to use their names for publicity for or to assert or imply endorsement
of any Modified Version.

   5. COMBINING DOCUMENTS

You may combine the Document with other documents released under this License,
under the terms defined in section 4 above for modified versions, provided
that you include in the combination all of the Invariant Sections 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 Invariant Sections 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."

   6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the 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 distribute 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.

   7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the 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 Modified Version 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 Cover Text requirement of section 3 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.

   8. TRANSLATION

Translation is considered a kind of modification, so you may distribute translations
of the Document under the terms of section 4. Replacing Invariant Sections
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.

   9. TERMINATION

You may not copy, modify, sublicense, or distribute the 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.

   10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation 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/.

Each version of the License is given a distinguishing version number. If the
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.
ADDENDUM: How to use this License for your documents

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 (c) 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 Invariant Sections being LIST THEIR TITLES , with the Front-Cover
Texts being LIST , and with the Back-Cover Texts being LIST . A copy of the
license is included in the section entitled "GNU Free Documentation License".

If you have no Invariant Sections, write "with no Invariant Sections" instead
of saying which ones are invariant. If you have no Front-Cover Texts, write
"no Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise
for Back-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, to permit their use in free software.