If a name is preceded by a slash, PostScript will place the name on the stack as an operand. If the name has no slash, the interpreter will look up its value in the dictionary stack. If the value is a procedure object, the procedure will be evaluated. If the value is not a procedure, the value will be pushed onto the operand stack. Number PostScript supports integers and reals.
Scientific notation is the standard mantissa E exponent form used in most languages.
String Strings are, of course, just strings of characters. There are two ways of expressing strings in Level 1 PostScript. The most common way is to wrap your text in parentheses. You can also express a string as hexidecimal codes in angle brackets. There are several escape codes that may be used in the parenthesis format of strings.