Some words on the forum have this dotted underline, you can hover over it with your mouse to get an explanation. Unfortunately it doesn’t work on touch screens.
FA stands for false awakening. It’s a dream in which you think that you woke up. In the end they are just dreams but with a somewhat special theme and the distinction gets blurry. I usually consider a dream a FA if it connects directly from sleep, so the start of the dream was me waking up in bed. Usually the next thing I’m doing is contemplating on my dreams and writing them down, much like I would in waking life. These kind of dreams seem to be more common among people invested in dreams, hence we have a dedicated term and acronym for it
I find them quite amusing although they tend to be a little annoying. You have an FA and write down your dreams. Then you wake up and write them down again. Then you wake up again. Oh no, it were 2 FAs! And write down dreams a third time
Not a rare occurrence this kind of time loop 
So I was dreaming that I got up in the middle of the night, visit the toilet, get something to drink, process my dream and start my meditation for MILD. But it never really happened. Only in the morning I realize it. So before I do MILD next time, I’ll try to remember RCing.
But maybe doing a MILD inside dreams can still yield a subsequent lucid dream. Maybe even more likely so as the incubation through intent should be more effective when you’re already operating at a subconscious level 