I was reading online some of the legal troubles in the US that can occur to recommend letter writers. I imagine that many of us are familiar with (at least some of the) FERPA regulations. We must obtain (in writing) a signed permission to use grades, and (at least according to one place I found) we are also required to inform the letter receiver not to convey that information to a third party without written consent.
At many receiving institutions, during the submission process there is a (sometimes large) legal disclaimer. At some institutions, this includes something to the effect of "Law prevents us from keeping your letter confidential. We will protect your identity, unless a court says we cannot. etc..."
Some employers keep a permanent file containing the recommend letters. As we all know, details over time become fuzzy, and so this seems to leave a letter writer open to litigation if details in the letter are disputed (by either a disgruntled employer or the one we write the letter for).
What protections exist for those who write recommend letters? In particular, can letter writers give a time limit to how long an employer may keep a letter? Apparently, in countries outside the US, letters of recommend are very short, to avoid legal issues.