GL XML Specs Licensing
Currently, glad-generated code is licensed under
> Any of Public Domain, WTFPL or CC0.

However, the XML specs files for OpenGL are
> Licensed under the Apache License, Version 2.0 (the "License");

Note that in vk.xml, there is an exception clause:
> As an exception, if you use this Software to generate code and portions of
this Software are embedded into the generated code as a result, you may
redistribute such product without providing attribution as would otherwise
be required by Sections 4(a), 4(b) and 4(d) of the License.

...which is not present in, for instance, gl.xml.

Is this okay, legally? I don't know any specifics about licensing and I'm assuming it's okay, but just to be safe.