Key to compatibility tables

Yes Supported completely and correctly
Almost Supported completely and correctly except for a minor issue
Incomplete Supported correctly but not completely
Alternative Supported in an alternative way.
Untestable Test doesn't work at all, usually because it depends on another method or property that is not supported
Minimal Just barely supported but unusable in practice.
Incorrect Returns incorrect object or value and becomes badly usable
Buggy Does something it should not do
No Not supported
Crash Crashes browser