For some types of medieval document, determining the dates covered by the record can be difficult. If the source is a literary, philosophic, or theological text, the date of composition is in the database. If the source is a chronicle or annal that covers many centuries, the database records dates for which the author’s information is likely to be historically accurate. For example, for a universal chronicle that starts with creation but was written in the 8th century, catalogers have looked through the chronicle to see when information starts being factual rather than legendary; for a universal chronicle of the 8th century this is likely to be sometime in the 6th century. Further information about the dating of a record will be found in the Comments field.