rel=logo is lovely.
I have a few ideas on making it better. The core idea is great, but if we're
pushing a new thing, we have an opportunity to encourage web developers to
provide more than just a single color logo. All of the ideas below are optional
enhancements for anybody wanting to use rel=logo on their site.
<!-- Encourage developers to provide monochrome renditions of their logo for
reproduction in environments without color. We can do this with rel="logo
monochrome", in much the same way as alternative stylesheets are specified
<link rel="logo monochrome"
<!-- We should be taking advantage of the existing media attribute to give hints
about the intended usage for a given logo. SVGs are great, but Facebook isn't
going to use an SVG as your site's image. Why not supply a PNG, sensibly sized
for the screen, with appropriate media definitions? Any site looking to fetch a
small logo to display can look for this standard link. -->