Like JeremyP, I have wondered what it means! However, I generally ignore that point, so some examples would help.
It's not really a question of examples rather about understanding that no matter how many facts you have to hand it doesn't tell you what you should do unless you have a goal or axiom of what you should do in order to make the decision, However, Alien, once of this parish, used an example when he was trying to illustrate that there was such a thing as objective morality that might be useful here since it posits something that he thought no one could disagree with,
The example was torturing a child to death just for fun, which was talked of so much that we shortened it to TACTDJFF. Unsurprisingly when people were asked whether they thought it was moral to do so, everyone who replied on the board said they didn't. Now Alien tried to use this apparent unanimity to argue for objective morality, a view denied buy most - but given that was a mega thread not the point here. Rather we have something where we have a child being murdered just because someone wants to have a bit of fun, That's the fact of the situation. From those facts alone can we say that is wrong? I don't see how.
However, if we have a base axiom that we should treat others like ourselves, and as an additional fact we wouldn't want to TTDJFF -then we can rationally argue that we should not TACTDJFF. Some person might however have the axiom that they should do whatever they want to feel good and could therefore if in addition to that they wanted to TACTDJFF, rationally decide to do that based on theit accepted axiom.