Well, if you need “instructions” how to decide wether you had a LD or a FLD, you probably either had no LDs or no FLDs so far. When you experience both it´s usually quite obvious.
The way you talk about LDs, and considering the fact how fascinated you are about them, I think that all users in here who don´t know how to identify a FLD simply only had “real” LDs.
(Ok, to differ between a real low-lucid dream and a FLD can be difficult).
Of course I can be wrong since I only know about my own feelings…
In a FLD, you have the knowledge that you are dreaming, yet you aren´t lucid. Usually, noticing that you are dreaming is accompanied by a change in counciousness (and often percpetion changes as well). This is often called “to awake in ones dream”.
In a FLD, you notice that you are dreaming, but still your dream-counciousness (or whatever you like to call it) is in full control. You recognize that you are dreaming, but this doesn´t cause you to wake up in your dream.
Unfortunately you can never tell for sure wether someone who´s describing a dream to you had a LD or a FLD, since the actions and thoughts can be exactly the same, but the feeling and state of counciousness is different.
tapir