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When the Obstacle data set (as specified in 5.3.3.2.2) is provided, certain sections of the AIP may be left blank and a reference to the data set availability shall be provided. In PANS-AIM these sections are marked with #AIP#OBS-DS# in PANS-AIM Appendix 2 "Contents of the Aeronautical Information Publication (AIP)" and they are also explicitly listed in the PANS-AIM section 5.2.1.1.4:
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