Abuild maintains a single variable symbol table. All variables are global, and all variables are visible to interface code of any item regardless of target type. Variables may be declared to apply to a specific target type. By default, they apply to all target types. When interface variables are passed to the backend, only variables declared in either the special target type all or in the item's own target type are made available.

In general, end users will not have to be concerned about which target types a variable applies to. A build item could, in principle, assign to both INCLUDES and abuild.classpath without having to care that only object-code items will see INCLUDES and only java items will see abuild.classpath.