diff --git a/src/Text/Pandoc/Readers/Mdoc.hs b/src/Text/Pandoc/Readers/Mdoc.hs
index 205438d171d2..d4874faf2743 100644
--- a/src/Text/Pandoc/Readers/Mdoc.hs
+++ b/src/Text/Pandoc/Readers/Mdoc.hs
@@ -1033,6 +1033,11 @@ parseDefinitionList = do
       after <- many1Till parseInlines (emptyMacro "Xc")
       spacify (before:after)
 
+-- TODO support implicit rows:
+--   If the first line of the body of a -column list is not an It macro line,
+--   It contexts spanning one input line each are implied until an It macro
+--   line is encountered
+-- and support literal tabs
 parseColumnList :: PandocMonad m => MdocParser m Blocks
 parseColumnList = do
   literal "-column"