<p dir="auto">Within the svg glyphicon, the id of the font is:</p>
<p dir="auto"><a href="https://github.com/twbs/bootstrap/blob/master/fonts/glyphicons-halflings-regular.svg#L6">https://github.com/twbs/bootstrap/blob/master/fonts/glyphicons-halflings-regular.svg#L6</a></p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&lt;font id=&quot;glyphicons_halflingsregular&quot; horiz-adv-x=&quot;1200&quot; &gt;"><pre class="notranslate"><code class="notranslate">&lt;font id="glyphicons_halflingsregular" horiz-adv-x="1200" &gt;
</code></pre></div>
<p dir="auto">However, in css, it is linked like so:</p>
<p dir="auto"><a href="https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less#L17">https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less#L17</a></p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="~&quot;url('@{icon-font-path}@{icon-font-name}.svg#glyphicons-halflingsregular') format('svg')&quot;;"><pre class="notranslate"><code class="notranslate">~"url('@{icon-font-path}@{icon-font-name}.svg#glyphicons-halflingsregular') format('svg')";
</code></pre></div>
<p dir="auto">When you disable all fonts but the svg variant, it displays in Safari 7 as little boxes. When you change the reference to an underscore, it displays fine in safari:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="~&quot;url('@{icon-font-path}@{icon-font-name}.svg#glyphicons_halflingsregular') format('svg')&quot;;"><pre class="notranslate"><code class="notranslate">~"url('@{icon-font-path}@{icon-font-name}.svg#glyphicons_halflingsregular') format('svg')";
</code></pre></div>
<p dir="auto"><a href="https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less#L17">https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less#L17</a></p>
<p dir="auto">This font face declaration is setup to reference the font name as a variable.<br>
However the SVG font ID after the hash is hard coded.</p>
<p dir="auto">Though this is not really an issue it could later become a problem if the font name and SVG font ID changes, and only the variable is updated and not properly tested.</p>
<p dir="auto">Will submit a PR that uses a new variable <code class="notranslate">@icon-font-svg-id</code></p>
<ul dir="auto">
<li>Edit *</li>
</ul>
<p dir="auto">Further more the font icon ID is incorrect<br>
<a href="https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less#L17">https://github.com/twbs/bootstrap/blob/master/less/glyphicons.less#L17</a><br>
<a href="https://github.com/twbs/bootstrap/blob/master/fonts/glyphicons-halflings-regular.svg#L6">https://github.com/twbs/bootstrap/blob/master/fonts/glyphicons-halflings-regular.svg#L6</a></p>
<p dir="auto"><code class="notranslate">glyphicons_halflingsregular</code> vs <code class="notranslate">glyphicons-halflingsregular</code></p>