This enumeration specifies types of mark modifications.

Values:

IG_ARTX_MODIFY_REASON_TEXT_EDIT	A text mark text attribute has changed.
IG_ARTX_MODIFY_REASON_RTF_EDIT	A rich text mark text attribute has changed.
IG_ARTX_MODIFY_REASON_ATTRIBUTE_CHANGE	A mark attribute has changed.
IG_ARTX_MODIFY_REASON_MOVE	The position of a mark has changed.
IG_ARTX_MODIFY_REASON_RESIZE	The dimensions of the mark bounding rectangle have changed.