The rules property retrieves a CSSRuleList (IHTMLStyleSheetRulesCollection) collection of rules defined in the respective CSSStyleSheet (IHTMLStyleSheet) object.
This collection is always accessible, even if the style sheet is not enabled. Rules are added to the rules collection with the addRule method on the style sheet. A rule that is added to a disabled style sheet does not apply to the document unless the style sheet is enabled. Rules are deleted with the removeRule method.