The document discusses the design and implementation of the second pass of a two-pass assembler. It explains that a two-pass assembler handles forward references easily by building a symbol table in the first pass and then using it to synthesize the target program in the second pass. The first pass constructs an intermediate representation using the symbol table, which the second pass then processes to generate the target code. The algorithm for the second pass is described, which involves processing the intermediate representation and writing the target code to an output file.