Nice write-up and some lovely trout! LDR, yes, long distance release which actually entails playing the fish for a bit. I've fished a lot over the years, and a good LDR can actually be rewarding, especially if it's from a really prized fish like a winter steelhead on the fly, or a massive brown or any cutthroat over, oh, let's say 16 inches (where I live).
But there are other terms too: "On-n-Gone", which is like a take, then a headshake or two, and an immediate loss of the fish.
And also "drive-by", which is a take or strike, but which results in absolutely NO hookup.