R is first_ASCII(String)
Here String has to be string. This function returns an integer whose value is equal to the ASCII code of the first character of the string. If the symbol is not in the ASCII table its code is bigger than 127 and the result of this function will depend on the default char set.
Note. Symbols which are in the ASCII table have codes from 0 to 127 and these codes are the same for all char sets. So, for these symbols the default char set is not important.
If the default char set is Unicode first_ASCII will return the Unicode number of the first symbol.
If the default char set is not Unicode first_ASCII will return integer between 0 and 255 whose value is equal to the code of this symbol in the default char set.