Clones -- are documents having equal values of Hash32 on all document sections. Indentical copies of the same document always have equal values of Hash32. This allow to eliminate duplicate documents in a collection. However, if only title section is defined in sections.conf, all documents with different bodies but with identical titles will be considered as clones.
Allow/disallow clone detection and eliminating. If allowed, indexer will detect the same documents under different location, such as mirrors, and will index only one document from the group of such equal documents. "DetectClones yes" also allows to reduce space usage. Default value is "yes".