2.1.1825 Part 4 Section 188.8.131.52, OLEObject (Embedded OLE Object)
a. The standard implies that the ObjectID attribute is used for all embedded objects.
Office does not support the ObjectID attribute for linked objects.
b. The standard indicates that the value of the ObjectID attribute is a string, but does not specify a format.
Office formats the string value for the ObjectID attribute as starting with "_" followed by a number in the range 0-2147483647.
c. The standard indicates how the ObjectID attribute is used.
Office generates a new value for the ObjectID attribute on each file save.
d. The standard indicates that the id, ObjectID, ProgID and ShapeID attributes are optional.
Office requires that the id, ObjectID, ProgID, and ShapeID attributes be specified for the OLEObject element, or else the embedded object is converted to a static image.