1. Multiple strong symbols are not allowed○ Each item can be defined only once2. Given a strong symbol and multiple weak symbols, choose the strong symbol○ References to the weak symbol resolve to the strong symbol3. If there are multiple weak symbols, pick an arbitrary one

● Global symbols○ Symbols defined by module m that can be referenced by other modules.■ e.g., non-static C functions and non-static global variables.● External symbols○ Global symbols that are referenced by module m but defined by some other module.● Local symbols○ Symbols that are defined and referenced exclusively by module m.■ e.g., C functions and global variables defined with the static attribute.○ Local linker symbols are not local program variables