• As a default, some compilers mark global variables as shared (SHR: every user who runs a program linked to the shareable image sees the same variable) and others mark them as not shared (NOSHR: every user who runs a program linked to the shareable image gets their own private copy of the variable).

• Some compilers support modifiers you can place in your source code variable declaration statements to explicitly state which attributes to assign a variable.

• The attributes that a compiler assigns to a variable can be overridden at link time with the psect_attr link option. This option overrides attributes of all variables in the psect.