OpenVMS I64 only.

    Establishes a temporary named or anonymous linkage that will
    be used by the compiler for the next CALLS, CALLG, JSB, BSBB,
    or BSBW instruction processed in lexical order. This directive
    is used when the target of the next CALLS, CALLG, JSB, BSBB,
    or BSBW instruction is not a name, but a run-time value (for
    example, CALLS #0, (R6)). When the compiler sees the next
    CALLS, CALLG, JSB, BSBB, or BSBW instruction, it will use the
    associated linkage to decide which registers need to be saved and
    restored around the call. After the instruction is processed, the
    temporary linkage is reset to null.

    Format

      .USE_LINKAGE  [linkage_name] [,input] [,output] [,scratch]

                    [,preserve]