Wow, I'm sorry if I have offended in some way. I can admit that I am new to the Latin translation process and find it daunting. I can also assure you that I have always done my own research. That is why I know that subsidium can be used in two senses, in the general sense of help, aid, support, etc., or in a more militant sense of reserve/auxiliary forces.
I also know that translation is not about the literal, but general meaning and that Renaissance humanists often played with the classical lexicon to add layers of meaning. I realize that the general literal translation of subsidium does not work for a dedication to the pope, which is why I went with defender even though defensor is not used.
Which is why, as part of MY research, I thought I would turn to those who are far more expert in these matters than I to ask their opinions and present the context of the quote to achieve the correct meaning.
Matthaeus, I wish to thank you for helping with the abbreviation question. That cleared up everything. I though an academic discussion of the intended meaning of subsidium would be welcome here. I am sorry if this or my admitted neophyte Latin has offended. I shall not bother you, again.