/sys$common/syshlp/helplib.hlb FORTRAN, Data, Constants, Character  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  A character constant is a string of printable ASCII characters
  enclosed by apostrophes.  A character constant has the form:

    'c1,c2,c3...cn'       c is a printable character.

  The length of the character constant is the number of characters
  between the apostrophes, except that two consecutive apostrophes
  represent a single apostrophe.  The length of a character constant
  must be in the range 1 to 2000.