Json Publication

{
"id" : "81b15c93-59e0-1392-8159-000000da0001",
"modified" : [ 2017, 3, 6, 0, 0 ],
"modifiedBy" : {...},
"agency" : {...},
"name" : "test",
"basedOnObject" : null,
"basedOnRevision" : null,
"version" : {...},
"changeKind" : "CREATED",
"changeComment" : null,
"purpose" : "test",
"status" : "Designmeeting 2",
"publicationElements" : [ {
  "id" : "1593ff7c-f2ad-4b6b-8bb2-f685cdf29571",
  "revisionNumber" : 400,
  "elementKind" : "QUESTION_ITEM",
  "element" : {...}
  }, {
  "id" : "081bb8ff-b800-416a-b851-612ee7c04b32",
  "revisionNumber" : 417,
  "elementKind" : "QUESTION_ITEM",
  "element" : {...}
  }],
}

element is never saved, and it is always populated when json is returned from the server. So what is needed from the client is (publicationElement):

id, revisionNumber & elementKind

publicationElements is an ordered list, the order you send them to the server is the order they are returend in.