In external style sheet files:
// external file mystyles1 P { color: yellow } .warning { color: red } <!-- link in <HEAD> to import --> <LINK REL=STYLESHEET TYPE="text/css" HREF="http://style.com/mystyles1" TITLE="Cool">
In this example, external style sheet file mystyles1 contains two declarations. A LINK element in the HTML file's HEAD links to mystyles1.
This is the best approach because it cleanly separates the formatting information (in the external style sheet file) from the content (in the HTML file) and means they can be edited independently, perhaps by different people.
It also makes it possible for many HTML files to share the same style sheet file. When that single style sheet file is changed, all the HTML files will inherit the new look and feel.