The corresponding AIXM 5.1.1 change proposal document concludes that there are no impact on existing AIXM 5.1 implementations because it's XLink item used it only in AIXM (xlink:href) is identical in old and new schema scale.
The corresponding AIXM 5.1.1 change proposal document concludes that there is no impact on existing AIXM 5.1 implementations, because the only XLink item used in AIXM (xlink:href) is identical in the old and new schema definition.