Common Block

[JohnNichols]

    COMMON nrhs

In the code I am using there is the common statement in two subroutines -- I always thought that a common block had to have a name?

[Steve_Lionel]

Nope - there is a thing called "blank COMMON" with slightly different semantics (you're allowed to have different lengths in different program units.) The more common (!) use of it in the past was for temporary variables where you didn't care if some other subroutine used the same memory.