The censorlogger telemetry Facebook sends back when you discard a post.

censorlogger.json

[
  {
    "user": "616672539",
    "page_id": "d38ums",
    "posts": [
      [
        "feed_tracking",
        {
          "ft": {
            "evt": 51,
            "qid": "5957677723697664915",
            "mf_story_key": "6097123472833952959",
            "fbfeed_location": 1
          }
        },
        1387130238116,
        0
      ],
      [
        "feed_tracking",
        {
          "ft": {
            "evt": 51,
            "qid": "5957677723697664915",
            "mf_story_key": "-1245002482402215432",
            "fbfeed_location": 1
          }
        },
        1387130238117,
        0
      ],
      [
        "censorlogger",
        {
          "cl_impid": "7a6d3366",
          "clearcounter": 0,
          "instrument": "composer",
          "elementid": "u_jsonp_3_g",
          "parent_fbid": 616672539,
          "version": "x"
        },
        1387130252416,
        0
      ]
    ],
    "trigger": "censorlogger"
  }
]