function plugindef()
   -- This function and the 'finaleplugin' namespace
   -- are both reserved for the plug-in definition.
   finaleplugin.RequireSelection = true
   finaleplugin.CategoryTags = "Layout, Measure, Rest"
   return "Create Tacet", "Create Tacet", "Creates a full tacet 'measure' for the selected region."
end

-- Load the multimeasure rest prefs
local mmrestprefs = finale.FCMultiMeasureRestPrefs()
mmrestprefs:Load(1)

-- Will not continue if auto-update of mm rests is ON
if mmrestprefs.AutoUpdate then
    print ("Automatic Update is ON in the multimeasure preferences.")
    return
end

local ui = finenv.UI()
if ui:AlertYesNo("Do you want to create a tacet section in this part? All music in the region will be hidden.", 
            "Are you sure?") ~= finale.YESRETURN then
    return
end

local region = finenv.Region()

-- Delete all old mm rests from the region
-- (In this case, it's safe to delete from the start, since no relocation of data records takes place.)
local mmrests = finale.FCMultiMeasureRests()
mmrests:LoadAll()
for mm in each (mmrests) do
    if region:IsMeasureIncluded(mm.StartMeasure) or region:IsMeasureIncluded(mm.EndMeasure) then        
        mm:DeleteData()
    end
end
 
local mm = finale.FCMultiMeasureRest()
mm.StartMeasure = region.StartMeasure
mm.EndMeasure = region.EndMeasure
-- Copy from the default MM rest definition
mm.NumberHorizontalAdjust = mmrestprefs.NumberHorizontalAdjust
mm.NumberVerticalAdjust = mmrestprefs.NumberVerticalAdjust
mm.ShapeEndAdjust = mmrestprefs.ShapeEndAdjust
mm.ShapeID = mmrestprefs.ShapeID
mm.ShapeStartAdjust = mmrestprefs.ShapeStartAdjust
mm.StartNumberingAt = 20000 -- A really high value here to hide the number
mm.SymbolSpace = mmrestprefs.SymbolSpace
mm.UseSymbols = mmrestprefs.UseSymbols
mm.UseSymbolsLessThan = mmrestprefs.UseSymbolsLessThan
mm.Width = mmrestprefs.Width
mm:Save()