ld.info: Symbols

Go forward to Location Counter
Go backward to Constants
Go up to Expressions
Go to the top op ld

Symbol Names

   Unless quoted, symbol names start with a letter, underscore, or
period and may include letters, digits, underscores, periods, and
hyphens.  Unquoted symbol names must not conflict with any keywords.
You can specify a symbol which contains odd characters or has the same
name as a keyword by surrounding the symbol name in double quotes:
       "SECTION" = 9;
       "with a space" = "also with a space" + 10;
   Since symbols can contain many non-alphabetic characters, it is
safest to delimit symbols with spaces.  For example, `A-B' is one
symbol, whereas `A - B' is an expression involving subtraction.