*
* <ul>
* <li><KeyResolver> elements with a type attribute
- * <li><MetadataFilter> elements with a type attribute
+ * <li><MetadataFilter> elements with a type attribute and type-specific content
* <li><Exclude> elements representing a BlacklistMetadataFilter
* <li><BlacklistMetadataFilter> element containing <Exclude> elements
* <li><Include> elements representing a WhitelistMetadataFilter
+ * <li><SignatureMetadataFilter> element containing a <KeyResolver> element
* <li><WhitelistMetadataFilter> element containing <Include> elements
* </ul>
*