I stumbled upon an issue mentioned in this
Kindle thread.
The user defined an embedded font in the
<style> section of an .html file and got the following FlightCrew error:
This resource is present in the OPF <manifest>, but it's not reachable (it's not unused).
However epubcheck doesn't report any errors and the embedded font shows up in ADE and KP (after compilation).
When I moved the style segment to a separate stylesheet and linked it to the .html file, FlightCrew no longer reported the error.
Here's the code:
Spoiler:
<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<style type="text/css">
@font-face {
font-family: 'Plain Back';
font-weight: normal;
font-style: normal;
src: url(../Fonts/plainback.ttf);
}
.dc {font-family: 'Plain Back';}
</style>
</head>
<body>
<p><span class="dc">T</span>his is weird.</p>
</body>
</html>
Is this a feature or a bug?