- Conditional processing conceptsWhen DITA content is processed to a reading format, rules to 	 exclude or highlight some of the content can be defined in a  	 ditaval file. This  	 conditional processing requires metadata attributes to be set 	 on DITA elements that may possibly be excluded or highlighted.     
- Condition (or select) attributesThe  	 audience,  	 platform,  	 product,  	 otherprops and  	 rev attributes can be applied to most DITA elements. They 	 are used for conditional processing, and are known as the  	 condition (or  	 select) attributes.     
- Filtering and flaggingContent marked with metadata attributes can be conditionally 	 processed so that the content is filtered (excluded) or flagged (highlighted) 	 in the published output.     
- Other metadataIn addition to the select attributes, DITA content includes many 	 forms of metadata. These metadata elements and attributes are used to manage 	 and  	 organise 	 topics, ditamaps and publications.     
- IndexingDITA incorporates powerful features for indexing, including 	 multi-level indexing, and  	 see andsee-also redirection. Index entries can be applied in the ditamap, 	 in the topic prolog, and inline within the topic content.