A list of one or more physical libraries which compose the virtual library. The order of the physical libraries is important. A module found in one physical library in the library list hides the same module in other physical libraries that come later in the library list. For example, suppose you have three libraries. Library 1 contains module A. Library 2 contains modules A, B, and C. Library 3 contains modules C and D. SCA uses module A from Library 1, modules B and C from library 2, and module D from library 3.