# CKEDITOR.filter.contentRule

class since 4.1.0 abstract

Virtual class representing CKEDITOR.filter.check argument.

This is a simplified version of the CKEDITOR.filter.allowedContentRules type. It may contain only one element and its styles, classes, and attributes. Only the string format and a CKEDITOR.style instances are accepted. Required properties are not allowed in this format.

Example:

'img[src,alt](foo)' // Correct rule.
'ol, ul(!foo)'      // Incorrect rule. Multiple elements and required
// properties are not supported.