I think it's relevant to point out that "for reference" is different from "by reference."
"For reference" means so you can refer to it.
"Incorporated herein by reference" means that the additional information legally becomes a part of the document itself. It's not something extra you might want to refer to--it is officially part of the document.
Wisconsinite makes an excellent point. An example: Document A mentions Document B and says that Document B is "hereby incorporated by reference." This means that Document A now officially, or legally, contains Document B, even if Document B is not copied into or attached to Document A in any way. Legally, anyone who uses Document A has the legal obligation to know what Document B says (even if they have to go somewhere else to find it), because Document A has "incorporated" Document B just by saying so. The "by reference" part is self-referential: it means that just by the act of referring to Document B, we have thereby incorporated it into the present Document A. ¿Podría algún forero confirmar que la sugerencia de Yoyi (en 2007) es lo adecuado para esta idea?