A \DtkLinkToFeaturePtrPtr can be construction or manufacturing feature see class info: Dtk_feat. It can be associated with any Dtk_Node type. Until now, Feature read is only available in CatiaV5, Ug NX, and ProE/Creo Parametric libraries and needs a specific licence.
See Feature mapping in readers menu :

readers
Sample to write a Dtk_Feature