ahem	A	Requires Ahem Font
dom	O	Requires DOM (Document Object Model) Support
font	F	Requires Special Font
history	H	Requires Session History
image	G	Requires Bitmap Graphics Support
interact	I	Requires User Interaction
invalid	invalid	Tests Invalid CSS
may	M	Behavior tested is preferred but optional
namespace	N	Requires XML Namespaces Support
paged	P	Test Only Valid for Paged Media
scroll	S	Test Only Valid for Continuous Media
should  R       Behavior tested is recommended but not required
svg	V	Requires SVG Support
96dpi	D	Assumes 96dpi