If an ARO layer is revised, because its end date, inflation rate, risk-free rate, or probability are changed mid- life, the original information on the layer is maintained for historical continuity and audit purposes, and the ARO is recalculated as of the date of the revision. The new revision has its effective date entered as the booking date; the prior revision has the date of change entered as the revision date. If this field is blank, it means that there are no further revisions for this layer.
