MQ's Level 4 : Update Frequency
You will be able to declare how something will look depending on the medias ability to update the display. None – printed paper that will never change, slow – e-ink readers that won’t show animations; normal – pretty much the default you would expect everything else to fall under.
The update-frequency media feature is used to query the ability of the output device to modify the apearance of content once it has been rendered
An excerpt from MQ's Level 4 : Update Frequency
