The root element. Can contain any amount of genetic information Establishes a relation on two or more items Temporal precedence Synchronicity if present and 'yes', this relation should not be considered when calculating datings Assigns a date or date range to an item Specifies the exact date The earliest possible date The latest possible date The starting point of the period The ending point of the period the period is the normalized form that represents a fuzzy interval like 'Spring 1798' An item that can be dated or related to another item. Items can be manuscripts, but also events or anything else with genetic significance. Any information that cannot be expressed in the formalisation. The source of the information. The URI identifying the source must be given. More bibliogrpahical detail (volume, page, ...) can be given inside the element. The URI identifying the source