VMS Help SCA, SCA Topics, Glossary, reference  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The use of some object in the source code. For example: X = X + 1
    In this example, there are two references to the variable X. One
    (to the left of the =) is a write reference; the other is a read
    reference. A reference has a position in the source code, but it
    is a single point and cannot contain anything.