which documents are required for DNI?

While I'm not applying for a DNI now, its possible I might sometime down the track. I'm going back to my home country next week and want to make the most of it - should i bring back some documents that i might need for the long process if I decide to undertake it in the future? If so, what do I need?thanks.
Tim,DNI is a document like an internal passport. People are applying for DNI after getting residency (radicacion). For radicacion you will need an apostilled original birth certificate. It can be a duplicate, issued by the same agency that normally gives them out, but it can not be a copy (not even a notarized copy). Since immigration takes your original birth certificate away in exchange for residency papers, and usually it gets lost, it makes sense to request a duplicate in your contry of origin.You will also need a document confirming that you don't have any criminal history in your country. Sometimes it is called criminal history report, sometimes it is called certificate of good conduct. Normally you can get it at a local police station. Get it apostilled as well.
Depending on the way you decide to pursue your residency, you may need some other documents as well I guess.
If I remember this all correctly then the documents have to have a certain "age" in order to be accepted for this process. Meaning that only fresh documents are accepted, might be misremembering things though. A very good question is however on what basis you are going to file for a DNI, the most popular way among expats is the rentista visa but for that you need to show an income and that you're transfering $ to Argentina.Best of luck