Hi Franco Actually the simple case of finding formatting tags in free text was easier in Parsec than my email last night suggested. Perhaps it is artificially easy because you can identify tag start and ends with a single character so you can use `satisfy`. import Text.Parsec import Text.Parsec.String import Control.Applicative hiding ( (<|>), many ) data Text1 = FreeText String | Formatted String deriving (Eq,Ord,Show) type Text = [Text1] runText :: String -> Either ParseError Text runText = runP lexer () "no-input" notLAngle :: Char -> Bool notLAngle = (/= '<') notRAngle :: Char -> Bool notRAngle = (/= '>') lexer :: Parser Text lexer = many (formatted <|> free) formatted :: Parser Text1 formatted = Formatted <$> between (char '<') (char '>') (many1 (satisfy notRAngle)) free :: Parser Text1 free = FreeText <$> many1 (satisfy notLAngle) demo01 = runText "[ someconditions | this is some <red - formatted> text.]" demo02 = runText "<red - formatted> more text."