Lately I've started wondering about the ¤ character which is shift+4 on my Norwegian keyboard (it's also present on several others, including the U.S. International keyboard layout). I've never seen a use for it, yet for some reason someone decided it was important enough to have it put in such a central place on the keyboard. What is this character called, and what purpose does it have?
This is the currency sign
A currency sign is a graphic symbol used as a shorthand for a currency's name.
Also from Currency (typography):
The currency sign (¤) is a character used to denote a currency, when the symbol for a particular currency is unavailable.
The symbol is available on some keyboard layouts, for example French, Danish, Norwegian, Swedish and Finnish keyboards, because it is used in business applications.
Pillow character in the Travel Industry designates a Guarantee Sell vendor. Allowing visual confirmation of booking a transaction with a vendor that guarantees reservation.
This is called a "pillow" and is used, at least, in some Global Distribution Systems for the Travel Industry.
Source: I work in the Travel Industry.