I understand the following phrase as follows:
how to not be seen – how to avoid being seen altogether
how not to be seen – how to avoid outfits or circumstances in which you do not want to be seen
But it’s rather ambiguous and perhaps it’s the other way around or just depends on context.
I’ve seen Order of "not" with infinitive, but it still feels like there is a difference in this case and that the meanings are different.
If you’re curious, this comes from a Monty Python sketch.
However yes, your second is ambiguous. It could mean either how to avoid outfits or circumstances in which you do not want to be seen but it could also mean exactly the same as the first.
Mental brackets might help, at least in the second case - which was where the problem lay, wasn't it?
Either way might need re-phrasing but do you see a clear difference in thought between how not to (be seen) and how not (to be seen)?
– Robbie Goodwin Dec 16 '17 at 20:43