planner generates the following type of events to capture the metadata in the dax into the bp file

static.meta.start - indicates start of metadata events
wf.meta - captures metadata events for the workflow
task.meta - captures metadata associated with the task in the DAX
rc.meta - captures metadata about a file
wf.map.fille - associates the workflow, file and task that generates it
static.meta.end - end of metadata events in the bp files

sample events
ts=2015-10-13T20:50:15.798371Z event=static.meta.start xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8

ts=2015-10-13T20:50:15.798692Z event=xwf.meta xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 key="name" value="diamond"
ts=2015-10-13T20:50:15.799129Z event=xwf.meta xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 key="createdby" value="Karan Vahi"

ts=2015-10-13T20:50:15.799603Z event=task.meta xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 task.id="ID0000004" key="time" value="60"
ts=2015-10-13T20:50:15.799907Z event=task.meta xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 task.id="ID0000004" key="transformation" value="analyze"

ts=2015-10-13T20:50:15.805293Z event=rc.meta xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 lfn.id="f.a" key="raw_input" value="true"
ts=2015-10-13T20:50:15.805593Z event=rc.meta xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 lfn.id="f.a" key="size" value="1024"

ts=2015-10-13T20:50:15.805993Z event=wf.map.file xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 task.id="ID0000001" lfn.id="f.a"
ts=2015-10-13T20:50:15.806300Z event=wf.map.file xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8 task.id="ID0000001" lfn.id="f.b2"

ts=2015-10-13T20:50:15.807098Z event=static.meta.end xwf.id=9ab8e307-4f05-4e45-bb9c-01ffda6e59f8