licensing open-source-software
SIL OFL License v1.1 and Embedding Icon Fonts in Software Binaries
<p>I am unclear on some of the nuances of the <a href="http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&amp;id=OFL" rel="nofollow noreferrer">OFL</a> when it comes to things like modifications and what that means in terms of permission to redistribute it.</p>

<p>My use-case is as follows:</p>

<p>I developed a plugin for an e-book type setting software which allows you to include vector images.  Essentially, you can hit a button and it positions the icon on the editor screen - ready for you to move/scale/rotate and apply a fill colour.</p>

<p>It is mostly designed for users to import their own vector libraries.</p>

<p>However, I am also playing with the thought of including some well-known OFL licensed icon sets - some 5,000 icons in total.</p>

<p>Here are the specs:</p>

<ol>
<li>I am deleting a couple of icons from each icon set - in turn meaning that I modified that font</li>
<li>The fonts are not re-distributed by themselves, but included in a "larger work" (my app)</li>
<li>The icons are not embedded in source form, but their SVG sprites are combined into one large icon set (SVG inside XML) and then compiled into a DLL.</li>
<li>When icons are added to the document, their SVG markup is extracted from my DLL, sometimes slightly modified (viewBox attribute) and added to the document.</li>
</ol>

<p>Now, my questions are:</p>

<ol>
<li>I want to show the icon's source/author in a status bar when it is selected (before adding it to the e-book) to attribute the authors:

<ol>
<li>But is this in keeping with the requirement to have to rename the icon set? I mean, I can't say "(c) FontSoAndSo 2017 by XYZ licensed under SIL OFL" because the license says I must rename it and I must not use their trademark.</li>
<li>If I can't mention their names, then I would rather like to remove any sort of attribution whatsoever, although I find that unfair. Would that be an alternative?</li>
</ol></li>
<li>The license also forbids sub-licensing - seeing as I am embedding the fonts in a wider piece of software, this point should be covered? The software has features besides inserting icons.</li>
<li>I must include the license:  does this only hold for actually distributing the font in a modified way and "as a font"? Does it also apply when embedding the font in a software application that is not a font, but facilitates the use of parts of that font?

<ol>
<li>If this does apply, I wonder if it would suffice to include a hyperlink to the SIL OFL.</li>
</ol></li>
</ol>

<p>The wording of the font name change requirement (3) in <a href="http://scripts.sil.org/cms/scripts/page.php?item_id=OFL_web" rel="nofollow noreferrer">the current license</a> is</p>

<blockquote>
  <p>No Modified Version of the Font Software may use the Reserved Font
  Name(s) unless explicit written permission is granted by the
  corresponding Copyright Holder. This restriction only applies to the
  primary font name as presented to the users.</p>
</blockquote>

<p>From what I can tell, their <em>intent</em> is that you cannot call a derived font the same thing as one of their fonts, so you cannot call your font "Doulos SIL". The <a href="http://scripts.sil.org/cms/scripts/render_download.php?format=file&amp;media_id=OFL-FAQ_plaintext&amp;filename=OFL-FAQ.txt" rel="nofollow noreferrer">OFL FAQ</a> explains (1.21) that "you must respect any names reserved by the font authors via the RFN mechanism and pick your own font name". Their <a href="http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&amp;id=OFL_web_fonts_and_RFNs" rel="nofollow noreferrer">discussion of RFNs</a> explains the reasons:</p>

<blockquote>
  <p>The RFN mechanism is an integral part of this OFL model. Use of it is
  not required, but it provides some key benefits:</p>
  
  <p>Avoids collisions - it greatly reduces the likelihood that a Modified
  Version would get confused with the Original Version, whether by an
  end user, someone bundling the font into a separate app or collection,
  or an application attempting to render a document that specifies a
  particular font.</p>
  
  <p>Protects authors - it requires any font that bears the RFNs retain the
  functionality and quality of the Original Version.</p>
  
  <p>Minimizes support - it enables authors to adequately support their
  fonts without the burden of troubleshooting fonts bearing the same
  name that might have been poorly modified.</p>
  
  <p>Encourages derivatives - it encourages separately-named branches to
  exist and be properly identified so that new, interesting enhancements
  can get reviewed and eventually merged back into the main project.</p>
</blockquote>

<p>You can see that they do not want you to "assign" your font the same name as their reserved font name, but that does not mean you cannot <em>mention</em> the source font (that is, they are using "use" informally, not intended to mean "include, in any shape"). FAQ item 3.1 also says</p>

<blockquote>
  <p>Remember that, when authors have reserved names via the RFN mechanism,
  <em>you need to change the internal names of the font</em> to your own font
  name when making your modified version even if it is just a small
  change</p>
</blockquote>

<p>There is no attribution requirement, and the FAQ 1.1.2 explicitly says attribution is not required though it is allowed ("Font authors may appreciate being mentioned in your artwork's acknowledgements alongside the name of the font, possibly with a link to their website, but that is not required"). This supports the understanding that mentioning a font name is allowed, just not assigning (and creating an ambiguity inside the font as to whose version it is).</p>

<p>License condition (2) says</p>

<blockquote>
  <p>Original or Modified Versions of the Font Software may be bundled,
  redistributed and/or sold with any software, provided that each copy
  contains the above copyright notice and this license.</p>
</blockquote>

<p>"Font Software"</p>

<blockquote>
  <p>refers to the set of files released by the Copyright Holder(s) under
  this license and clearly marked as such. This may include source
  files, build scripts and documentation.</p>
</blockquote>

<p>"Modified Version"</p>

<blockquote>
  <p>refers to any derivative made by adding to, deleting, or substituting
  — in part or in whole — any of the components of the Original Version,
  <em>by changing formats</em> or by porting the Font Software to a new environment.</p>
</blockquote>

<p>So a narrow reading of what they say would lead you to conclude that the license propagation requirement does not just mean "as a font". But their FAQ suggests a different intent. Point 1.1 says:</p>

<blockquote>
  <p>Can I use the fonts for a book or other print publication, to create
  logos or other graphics or even to manufacture objects based on their
  outlines?</p>
  
  <p>Yes. You are very welcome to do so. Authors of fonts released under
  the OFL allow you to use their font software as such for any kind of
  design work. No additional license or permission is required</p>
</blockquote>

<p>...</p>

<blockquote>
  <p>1.1.1  Does that restrict the license or distribution of that artwork?</p>
  
  <p>No. You remain the author and copyright holder of that newly derived
  graphic or object. You are simply using an open font in the design
  process. <em>It is only when you redistribute, bundle or modify the font
  itself that other conditions of the license have to be respected</em> (see
  below for more details).</p>
</blockquote>

<p>1.13 also says</p>

<blockquote>
  <p>The requirement for fonts to remain under the OFL does not apply to
  any document created using the fonts and their derivatives. Similarly,
  <em>creating any kind of graphic using a font under OFL does not make the
  resulting artwork subject to the OFL</em>.</p>
</blockquote>

<p>The technicals of what you intend to distribute are not clear: if you're "copying code" then including a license would be required, and if you're just "using the artwork" then it probably is not (given the evidence of the FAQ).</p>

<p>License linking is explained in 1.10</p>

<blockquote>
  <p>The only situation in which an OFL font can be distributed without the
  text of the OFL (either in a separate file or in font metadata), is
  when a font is embedded in a document or bundled within a program. In
  the case of metadata included within a font, it is legally sufficient
  to include only a link to the text of the OFL on
  <a href="http://scripts.sil.org/OFL" rel="nofollow noreferrer">http://scripts.sil.org/OFL</a>, but we strongly recommend against this.
  Most modern font formats include metadata fields that will accept the
  full OFL text, and full inclusion increases the likelihood that users
  will understand and properly apply the license.</p>
</blockquote>

<p>They do not have a particularly stable web structure (things are constantly being renamed and moved, so URL references are probably only good for a few years).</p>

<p>(in accordance with the requirements of their FAQ, I hereby declare: "From the OFL FAQ (OFL-FAQ.txt), copyright (c) 2005-2017 SIL International. Used by permission. <a href="http://scripts.sil.org/OFL-FAQ_web" rel="nofollow noreferrer">http://scripts.sil.org/OFL-FAQ_web</a>")</p>
