In ArcGIS for Desktop (10.2.2) using the Maplex labelling engine, layers can be configured to NOT flip automatically. This option appears in the Label Rotation Dialog. I have been unsuccessful finding the value for a given layer from within ArcObjects. I have searched for the property on MaplexLabelEngineLayerProperties and on its OverposterLayerProperties. I've successfully located all of the other label position/rotation properties available on the Label Rotation dialog, except for the setting to Keep Label Upright. Any assistance directing me to where this property is exposed is greatly appreciated.