[AnrDaemon]

Does that mean that I can do something like

local frame = CreateFrame("GameTooltip", "MyPrivateStuff_QuestInfoTooltipFrame", UIParent, "GameTooltipTemplate")
 
function frame:GetQuestTitle()
  local title = MyPrivateStuff_QuestInfoTooltipFrameTextLeft1:GetText()
  DEFAULT_CHAT_FRAME:AddMessage(self["message"]:format(title))
  self:SetScript("OnTooltipSetQuest", nil)
end
 
-- Add some slashes sausage
local function commandHandler(msg, self)
  local argv = { strsplit(" ", strtrim(msg)) }
  if argv[1] == "quest" then
    if IsQuestFlaggedCompleted(argv[2]) then
      frame["message"] = ("Quest |cffffff00|Hquest:%d|h[%%s]|h|r flagged as completed."):format(argv[2])
    else
      frame["message"] = ("Quest |cffffff00|Hquest:%d|h[%%s]|h|r is not completed or not available to character."):format(argv[2])
    end
    frame:SetScript("OnTooltipSetQuest", frame.GetQuestTitle)
    frame:SetOwner(UIParent, "ANCHOR_NONE")
    frame:SetHyperlink("quest:" .. argv[2])
  end
end
 
SlashCmdList["MYPRIVATESTUFF"] = commandHandler
SLASH_MYPRIVATESTUFF1 = '/my'

? Anyone see anything apparently wrong with such logic? Or I can go for field testing?