[whatwg] HTML as a text format: Should <title> be optional?

[Kristof Zelechovski]

The DOCTYPE is required and it should be.  That way, the text introduces
itself and instructs the reader about the expected renderer (in absence of
external metadata).
I have seen several products (mail readers and proxies, on-line help
systems, fora etc.) trying to interpret every text as HTML, even if that was
not what the author intended.  It is safer to interpret every text as plain,
unless it starts with a DOCTYPE prologue.  This is especially important with
HTML fragments.
Chris