What is that character called?

If you look around your keyboard, you will notice a number of keys with characters on that you may not know the name of. In this post I will tell you the most common names for those esoteric characters. I am only looking at those characters that appear on my UK qwerty keyboard. I will explore those special characters and symbols that don't appear on the keyboard in future posts.

¬
This is called 'not' and is most commonly used in propositional logic and mathematics. It may not appear on all keyboards.

¦ and |
'Vertical bar' or 'pipe' is used in mathematics and computer programming. It can be 'broken' or 'unbroken' as shown.

^
'Caret' a.k.a 'hat', 'wedge' and 'chevron' is used in mathematics, logic, computing and to indicate ordinals in Italian.

~
'Tilde' is used in a variety of ways, such as indicating an approximation as well as the usual suspects: mathematics, logic and computing.