There's no good place to quickly search for weird HTML, CSS, and JS quirks in mobile devices. Let's fix that.
Please add any legitimate non-framework-specific browser issues to this tracker. We're using the term "device" broadly here - anything that runs a browser is a device, so feel free to file desktop browser bugs as well. If the issue deals with a browser in active development, it'd be very helpful to file the issue with that browser's tracker as well (but still file it here too!).
This site gives more information on filing browser issues: http://movethewebforward.org/
Of particular interest here are bugs in older platforms that are no longer being developed, but still come included on brand new devices - and often have no update path! Android 2.x WebKit quirks are a prime example.
Feel free to use this template, filling in all the sections you can: