Found this in the UI forum. Can't test anything at work... and some of it looks old as it references LFG not LFD.
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From the new LFD Tool:

inParty, joined, queued, noPartialClear, achievements, lfgComment, slotCount = GetLFGInfoServer();
voteInProgress, didVote, myVote, targetName, totalVotes, bootVotes, timeLeft = GetLFGBootProposal();
canBeTank, canBeHealer, canBeDPS = GetAvailableRoles();
leader, tank, healer, dps = GetLFGRoles();
inProgress, slots, members = GetLFGRoleUpdate();
{name, typeID, minLevel, maxLevel, expansionLevel, groupID, texture, difficulty} = LFDGetDungeonInfoByID(dungeonID);
JoinRandomDungeon();
ClearAllLFGDungeons();
JoinLFG();
SetLFDDungeonEnabled(dungeonID, isEnabled);
proposalExists, typeID, id, name, texture, role, hasResponded, totalEncounters, completedEncounters, numMembers = GetLFGProposal();
bossName, texture, isKilled = GetLFGProposalEncounter(i);
GetLFDRewardInfo(rewardID);
isLeader, role, level, responded, accepted, name, class = GetLFGProposalMember(memberID);
hasData, leaderNeeds, tankNeeds, healerNeeds, dpsNeeds, instanceType, instanceName, playersInQueue, partiesInQueue, averageWait, matchesMade, someTimeValue= GetLFGQueueStats();
LFDDungeonInfo = GetLFDChoiceInfo(); --Table
LFDCollapseList = GetLFDChoiceCollapseState(); --Table
LFDEnabledList = GetLFDChoiceEnabledState(); --Table
LFDDungeonList = GetLFDChoiceOrder(); --Table
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