+### `--txt`
+Generate text with ANSI coloring escape sequences.
+
+Instead of HTML, this generate text files with ANSI escape sequence for colors.
+The options `-f`, `--line-id-prefix` and `--ast` are ignored in this mode.
+
+### `-f`, `--fragment`
+Omit document header and footer.
+
+By default, a complete autonomous HTML document is generated.
+If `-f` is given, only the inside of the body part is generated such that it could be integrated
+into a HTML document.
+
+### `--line-id-prefix`
+Prefix of the id of each line `<span>` element.
+
+By default, each line is enclosed in its own `<span>` element with an `id` attribute made of the line number prefixed by `L` (e.g. `L1` for the first line).