Optional
Internal
clickableuriOptional
Internal
collectionOptional
Internal
connectortypeOptional
Internal
dateOptional
Internal
documenttypeOptional
Internal
filetypeOptional
Internal
languageOptional
Internal
objecttypeOptional
Internal
parentsOptional
Internal
permanentidOptional
Internal
sizeOptional
Internal
sourceOptional
Internal
sourcetypeInternal
urihash
Custom keys that depend on the documents in the index.