local p = {}  local data = mw.loadData("Module:ISO 3166/data/National")  function p.list(frame) --Returns a list of subpages and associated countries local codes = {} for alpha2,cdata in pairs(data) do  codes[#codes+1] = {alpha2,cdata.name} end table.sort(codes, function(t1,t2) return t1[1]<t2[1] end)  local out = {"* [[Module:ISO 3166/data/National|National]]"} for _,cdata in ipairs(codes) do  out[#out+1] = "* [[Module:ISO 3166/data/"..cdata[1].."|"..cdata[1].." ("..cdata[2]..")]]" end return table.concat(out,"\n")  end  function p.subpagetest(frame) --Returns a table row indicating the existence of data pages (see [[User:SiBr4/sandbox#Data subpage test]])  local function cell(code,d)  local sdata  if not data[code] then  return "" --Unassigned or reserved 3166-1 code  else  local sname = "Module:ISO 3166/data/"..code  if not (d or mw.title.new(sname).exists) then  return "title=\""..data[code].name.."\" style=\"background:#fee;\"|[["..sname.."|-]]" --Data subpage doesn't exist  else  sdata = mw.loadData(sname)  end  end  for _,_ in pairs(sdata) do  return "title=\""..data[code].name.."\" style=\"background:#efe;\"|n" --Non-empty 3166-2 entry  end  return "title=\""..data[code].name.."\" style=\"background:#eef;\"|e" --Empty 3166-2 entry end  local letter = frame.args[1] local out = "|-\n!"..letter.."*" for i = 65, 90 do  out = out.."\n|"..cell(letter..string.char(i),frame.args[2]) end return out  end  function p.testall(frame) --Search across all subpages for problems with names  local strip = require("Module:ISO 3166").strip  local function subpage(p)  return "[[Module:ISO 3166/data/"..p.."|/"..p.."]]" end local function testname(names,inames,dnames,page,code,name)  if name then  if type(name)~="string" then  dnames[#dnames+1] = "*Unexpected non-string value in "..subpage(page).." ("..code..")"  else  local sname = strip(name)  if not names[sname] then  inames[sname] = name  else  dnames[#dnames+1] = "*Duplicate name: \""..name.."\" in "..subpage(page)  ..(names[sname]==name and " (exact)" or " (non-exact)").." ("..code..")"  end  end  end  return names, inames, dnames end local function testnametable(names,inames,dnames,page,code,tab)  if tab then  if type(tab)~="table" then  dnames[#dnames+1] = "*Unexpected non-table value in "..subpage(page).." ("..code..")"  else  for _,name in pairs(tab) do  names, inames, dnames = testname(names,inames,dnames,page,code,name)  end  end  end  return names, inames, dnames end local fields = {name=1,isoname=1,isonames=1,displayname=1,isodisplayname=1,isodisplaynames=1,altnames=1,lang=1,defaultlang=1,alpha3=1,numeric=1,nocode=1} local function testentry(names,dnames,page,code,edata)  for k,_ in pairs(edata) do  if not fields[k] then  dnames[#dnames+1] = "*Unknown field \""..k.."\" in "..subpage(page).." ("..code..")"  end  end  local inames = {}  names, inames, dnames = testname(names,inames,dnames,page,code,edata.name)  names, inames, dnames = testname(names,inames,dnames,page,code,edata.isoname)  names, inames, dnames = testnametable(names,inames,dnames,page,code,edata.isonames)  names, inames, dnames = testnametable(names,inames,dnames,page,code,edata.altnames)  if not edata.nocode then  names, inames, dnames = testname(names,inames,dnames,page,code,code)  end  if page=="National" then  names, inames, dnames = testname(names,inames,dnames,page,code,edata.alpha3)  names, inames, dnames = testname(names,inames,dnames,page,code,edata.numeric)  end  for k,v in pairs(inames) do names[k]=v end  return names, dnames end  local dnames = {}  --ISO 3166-1 local names = {} for code,cdata in pairs(data) do  names, dnames = testentry(names,dnames,"National",code,cdata) end  --ISO 3166-2 for code,_ in pairs(data) do  names = {}  local spage = "Module:ISO 3166/data/"..code  if mw.title.new(spage).exists then  local sdata = mw.loadData(spage)  for scode,cdata in pairs(sdata) do  if type(cdata)=="table" then  names, dnames = testentry(names,dnames,code,scode,cdata)  end  end  end end  if #dnames>0 then  return table.concat(dnames,"\n") else  return "None" end  end  return p