I'm getting my Software Engineer degree in one year here in my country, and I want to continue my studies with a Master degree in the US. Since here in my country is not a common practice to ask or write such letters, I'm not sure about some details. I have two main concerns about them:
1) How important is the written date of the letter? (It's OK to get one now, dated accordingly, if I will be submitting it in say, 2 years?)
2) Must the letter be always addressed? (It's OK to be generic, not addressed at anyone in particular? -At this moment I don't know what University I would like to apply-)
I'm asking those two questions because currently I'm developing an important software for the local Police (the 911 emergency line) and I think this could be a nice vouch for my technical skills, however since I'm changing jobs in a few weeks it's possible I won't stay in touch anymore with the Chief, or maybe this Chief won't be around in the future to ask him. This also because now I can ask for it and get it in paper, with the official letterhead and seal/stamp, so that will be a proof of authenticity.
Let's say my idea is to get this letter now and save it for later. Of course this would be a field expertise type of letter. Thanks!