diff --git a/ldoc.lua b/ldoc.lua
index 8481ebb..838caee 100644
--- a/ldoc.lua
+++ b/ldoc.lua
@@ -130,6 +130,8 @@ local file_types = {
 -- the ldoc table represents the API available in `config.ld`.
 local ldoc = { charset = 'UTF-8' }
 local add_language_extension
+-- hacky way for doc module to be passed options...
+doc.ldoc = ldoc
 
 local function override (field)
    if ldoc[field] ~= nil then args[field] = ldoc[field] end
@@ -193,8 +195,8 @@ local ldoc_contents = {
    'alias','add_language_extension','new_type','add_section', 'tparam_alias',
    'file','project','title','package','format','output','dir','ext', 'topics',
    'one','style','template','description','examples', 'pretty', 'charset', 'plain',
-   'readme','all','manual_url', 'ignore', 'colon', 'sort', 'module_file',
-   'boilerplate','merge', 'wrap', 'not_luadoc', 'template_escape',
+   'readme','all','manual_url', 'ignore', 'colon', 'sort', 'module_file','vars',
+   'boilerplate','merge', 'wrap', 'not_luadoc', 'template_escape','merge_error_groups',
    'no_return_or_parms','no_summary','full_description','backtick_references', 'custom_see_handler',
    'no_space_before_args',
 }
@@ -373,6 +375,10 @@ override 'merge'
 override 'not_luadoc'
 override 'module_file'
 
+if ldoc.merge_error_groups == nil then
+   ldoc.merge_error_groups = 'Error Message'
+end
+
 -- ldoc.module_file establishes a partial ordering where the
 -- master module files are processed first.
 local function reorder_module_file ()
diff --git a/ldoc/doc.lua b/ldoc/doc.lua
index 656b5f7..615abb8 100644
--- a/ldoc/doc.lua
+++ b/ldoc/doc.lua
@@ -21,7 +21,7 @@ local TAG_MULTI,TAG_ID,TAG_SINGLE,TAG_TYPE,TAG_FLAG,TAG_MULTI_LINE = 'M','id','S
 --  - 'N' tags which have no associated value, like 'local` (TAG_FLAG)
 --  - 'T' tags which represent a type, like 'function' (TAG_TYPE)
 local known_tags = {
-   param = 'M', see = 'M', usage = 'ML', ['return'] = 'M', field = 'M', author='M',set='M';
+   param = 'M', see = 'M', comment = 'M', usage = 'ML', ['return'] = 'M', field = 'M', author='M',set='M';
    class = 'id', name = 'id', pragma = 'id', alias = 'id', within = 'id',
    copyright = 'S', summary = 'S', description = 'S', release = 'S', license = 'S',
    fixme = 'S', todo = 'S', warning = 'S', raise = 'S', charset = 'S',
@@ -130,11 +130,11 @@ local acount = 1
 
 function doc.expand_annotation_item (tags, last_item)
    if tags.summary ~= '' then return false end
+   local item_name = last_item and last_item.tags.name or '?'
    for tag, value in pairs(tags) do
       if known_tags._annotation_tags[tag] then
          tags:add('class','annotation')
          tags:add('summary',value)
-         local item_name = last_item and last_item.tags.name or '?'
          tags:add('name',item_name..'-'..tag..acount)
          acount = acount + 1
          return true
@@ -435,10 +435,16 @@ function Item:set_tag (tag,value)
 
    if ttype == TAG_MULTI or ttype == TAG_MULTI_LINE then -- value is always a List!
       local ovalue = self.tags[tag]
-      if is_list(ovalue) then
-         ovalue:append(value)
+      if ovalue then -- already defined, must be a list
+         --print(tag,ovalue,value)
+         if is_list(value) then
+            ovalue:extend(value)
+         else
+            ovalue:append(value)
+         end
          value = ovalue
       end
+      -- these multiple values are always represented as lists
       if not is_list(value) then
          value = List{value}
       end
@@ -835,6 +841,8 @@ function Item:return_type(r)
    return r.type, r.ctypes
 end
 
+local struct_return_type = '*'
+
 function Item:build_return_groups()
    local modifiers = self.modifiers
    local retmod = modifiers['return']
@@ -849,11 +857,13 @@ function Item:build_return_groups()
          groups:append(group)
          lastg = g
       end
+      --require 'pl.pretty'.dump(ret)
       group:append({text=ret, type = mods.type or '',mods = mods})
    end
    -- order by groups to force error groups to the end
    table.sort(groups,function(g1,g2) return g1.g < g2.g end)
    self.retgroups = groups
+   --require 'pl.pretty'.dump(groups)
    -- cool, now see if there are any treturns that have tfields to associate with
    local fields = self.tags.field
    if fields then
@@ -861,24 +871,28 @@ function Item:build_return_groups()
       for i,f in ipairs(fields) do
          local name, comment = self:split_param(f)
          fields[i] = name
-         fcomments[i] = coment
+         fcomments[i] = comment
       end
       local fmods = modifiers.field
       for group in groups:iter() do for r in group:iter() do
-         if r.mods and r.mods.type  == '*'  then
-            local ctypes = List()
-            for i,f in  ipairs(fields) do
+         if r.mods and r.mods.type  then
+            local ctypes, T = List(), r.mods.type
+            for i,f in  ipairs(fields) do if fmods[i][T] then
                ctypes:append {name=f,type=fmods[i].type,comment=fcomments[i]}
-            end
+            end end
             r.ctypes = ctypes
+            --require 'pl.pretty'.dump(ctypes)
          end
       end end
    end
 end
 
+local ecount = 0
+
 -- this alias macro implements @error.
 -- Alias macros need to return the same results as Item:check_tags...
 function doc.error_macro(tags,value,modifiers)
+   local merge_groups = doc.ldoc.merge_error_groups
    local g = '2' -- our default group id
    -- Were we given an explicit group modifier?
    local key = integer_keys(modifiers)
@@ -888,14 +902,36 @@ function doc.error_macro(tags,value,modifiers)
       local l = tags:get 'return'
       if l then -- there were returns already......
          -- maximum group of _existing_ error return
-         local grp, text = 0, List()
+         local grp, lastr = 0
          for r in l:iter() do if type(r) == 'table' then
-            grp = math.max(grp,r.modifiers._err or 0)
-            text:append(r[1])
+            local rg = r.modifiers._err
+            if rg then
+               lastr = r
+               grp = math.max(grp,rg)
+            end
          end end
          if grp > 0 then -- cool, create new group
-            g = tostring(grp+1)
-            text:append(value)
+            if not merge_groups then
+               g = tostring(grp+1)
+            else
+               local mods, text, T = lastr.modifiers
+               local new = function(text)
+                  return mods._collected..' '..text,{type='string',[T]=true}
+               end
+               if not mods._collected then
+                  text = lastr[1]
+                  lastr[1] = merge_groups
+                  T = '@'..ecount
+                  mods.type = T
+                  mods._collected = 1
+                  ecount = ecount + 1
+                  tags:add('field',new(text))
+               else
+                  T = mods.type
+               end
+               mods._collected = mods._collected + 1
+               return 'field',new(value)
+            end
          end
       end
    end
diff --git a/ldoc/html.lua b/ldoc/html.lua
index cdc77fa..9a92ec2 100644
--- a/ldoc/html.lua
+++ b/ldoc/html.lua
@@ -168,7 +168,7 @@ function html.generate_output(ldoc, args, project)
    end
 
    function ldoc.typename (tp)
-      if not tp or tp == '' then return '' end
+      if not tp or tp == '' or tp:match '^@' then return '' end
       local optional
       -- ?<type> is short for ?nil|<type>
       if tp:match("^%?") and not tp:match '|' then
diff --git a/tests/styles/multiple.lua b/tests/styles/multiple.lua
index bd935fb..85e12b9 100644
--- a/tests/styles/multiple.lua
+++ b/tests/styles/multiple.lua
@@ -27,9 +27,13 @@ function mul3 () end
 -- @string name
 function mul4 (name)
     if type(name) ~= 'string' then
-        --- @error not a string
+        --- @error[1] not a string
         return nil, 'not a string'
     end
+    if #name == 0 then
+        --- @error[2] zero-length string
+        return nil, 'zero-length string'
+    end
     --- @treturn string converted to uppercase
     return name:upper()
 end
diff --git a/tests/styles/struct.lua b/tests/styles/struct.lua
index 9d454a2..c28689a 100644
--- a/tests/styles/struct.lua
+++ b/tests/styles/struct.lua
@@ -5,8 +5,9 @@
 -----
 -- returns a 'struct'.
 -- @string name your name dammit
--- @treturn * details of person
--- @tfield string name of person
--- @tfield int age of person
+-- @tfield string arb stuff
+-- @treturn st details of person
+-- @tfield[st] string name of person
+-- @tfield[st] int age of person
 function struct(name) end