• extent refers to the part of the work, image or collection being described by the element or sub-element that it modifies.
• href refers to a hypertext reference that provides a link to another electronic resource.
• pref indicates that a particular data value is the preferred value when multiple data values for the same element or subelement exist.
• refid refers to id numbers or codes coming from the local institution or resource named in the source attribute.
• rules refers to any data content standards used to construct the value recorded in the element (e.g. AACR2, CCO).
• source refers to the local, print, or electronic source from which information is derived for a specific element (e.g. Grove Dictionary of Art). Please note: SOURCE is also used as an element and should be used when you want to record a single print or electronic source for information pertaining to the entire record rather than pertaining to individual elements.
• vocab refers to the controlled vocabulary source from which the term or phrase is recorded (e.g. AAT, LCSH).
• xml:lang refers to the language in which the information is recorded in the system (e.g. English, French).