A.2.3 Character Strings
Entering character strings.
Character strings can contain any sequence of 8- or 16-bit characters. Characters entered by name or character code are stored the same as if they were entered directly.
Single newlines followed by spaces or tabs are converted to a single space when a string is entered, unless these characters occur within \< ... \>, in which case they are left unchanged.
Within \!\( ... \) any box structures represented using backslash sequences can be used.