LWASM supports generating a proprietary object file format which is described in Chapter 5. LWLINK is then used to link these object files into a final binary in any of LWLINK's supported binary formats.
Object files are very flexible in that they allow references that are not known at assembly time to be resolved at link time. However, because the addresses of such references are not known, there is no way for the assembler has to use sixteen bit addressing modes for these references. The linker will always use sixteen bits when resolving a reference which means any instruction that requires an eight bit operand cannot use external references.
Object files also support the concept of sections which are not valid for other output types. This allows related code from each object file linked to be collapsed together in the final binary.