What is the Correct Usage of Non & None, Use etc

[engtip8]

Kindly advise which is correct or the exact or better way to express the following:-

1) None Engineering Forum or Non Engineering Forum or....?
2) Please close the lip after use or Please close the lip after using or Please close the lip after used. or..?
3) .... unless stated otherwise or ....... unless otherwise stated?

Thank you for your advice.

[Ann1977]

1) None Engineering Forum or Non Engineering Forum or....?
Non-Engineering Forum

But ? might be the right choice, depending on what you want to express
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2) Please close the lip after use or Please close the lip after using or Please close the lip after used. or..?
Please close lid after use
NOTE: Probably the word is "lid," not "lip." Here are images of "lids"
lid - Google Images

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3) .... unless stated otherwise or ....... unless otherwise stated?
....unless otherwise stated.