Unused dependencies can be determined using ldd(1). See the -u option.
Various ELF ABI extensions have been added. See "Initialization and Termination Sections", "Initialization and Termination Routines", Table 7-4, Table 7-7, Table 7-14, Table 7-15, "Section Groups", Table 7-17, Table 7-21, Table 7-42, Table 7-43, and "Program Loading (Processor-Specific)".
Greater flexibility in the use of link-editor environment variables has been provided with the addition of _32 and _64 variants. See "Environment Variables".