The style sheets can specify how a document is to be presented on different media: on the screen, on paper, speech synthesizer, etc. You can specify that some of the features of your CSS stylesheet should be taken into account only in the Oxygen XML Author Author and ignored in the rest. This can be accomplished by using the media type oxygen.
For instance using the following CSS:
b{ font-weight:bold; display:inline; } @media oxygen{ b{ text-decoration:underline; } }
would make a text bold if the document was opened in a web browser that does not recognize @media oxygen and bold and underlined in Oxygen XML Author Author.
You can use this media type to group specific Oxygen XML Author CSS features and also to hide them when opening the documents with other viewers.