Electronic – What does ‘resist’ mean in this IC datasheet

That's the new politically correct way of writing numbers that would normally have decimal points. Some parts of the world (Germany for example) use a comma to separate the integer and fraction digits. To avoid ambiguity in international situations, some people now put the letter for the units where the decimal point should be. So "3V3" really means 3.3 Volts and "1V8" means 1.8 Volts.

If your audience is English speaking or it is obvious the document or the context is in English, then you are fine using a decimal point normally. After all, using a decimal point is part of the language no less than the words used to describe other things, so this is not ambiguous. In rare cases when numbers are by themselves without a language context, then it's probably best to use the "3V3" type notation. Otherwise, I personally find this notation rather annoying since I have to look at it and think about it rather than the brain parsing it without much conscious thought.

As with most things PC, it's about choosing which group of people to piss off.

NOM = Nominal, that's the value you normally can expect, and what the device is designed to.

Note that nominal values are often not the best to calculate with. If you want to go worst case you'll have to calculate with Minimum or Maximum, depending on the parameter and the application.