The METS root element has five optional XML attributes: two, ID and OBJID
(Object Identifier), identify the METS document; TYPE specifies what type of object is being documented; LABEL identifies the title of the object; and PROFILE which specifies which, if any, registered METS profile is being used.
Each entry is of the form (MBR, ObjID
), such that MBR is the minimum bounding rectangle that spatially contains the object and ObjID
is the objects identifier;