Paragraph spacing is a setting per document here. I can either shift enter or change my document's paragraph spacing.
Something that's been bugging me sometimes and now my husband just asked me about it is.....a lot of times when I post in forums, or in my email or in word, etc. I have to do Shift + Enter to not get spacing. My husband was just typing in Word 365 and I had to show him that trick. We are on Windows computers. Had to show him to backspace first to close up the lines and then do Shift+Enter to put the next line on the very next line and not to double space it.
You know what I'm talking about?

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