What do you mean encoding? Encoding would have a plethora of meanings.

You mean adding different characters using something other than standard html?
Like html5? xml? or something even rarer?

Google reads just about everything, but you take a chance on a person's
browser not showing anything properly.

But then, you claim content is plain text...

You gotta explain what you mean by encoding, cuz the question makes
little sense out of context.

Paul