On its own, FYI is a lazy move.
We like to tell ourselves that it’s a form of giving. That we’re passing on something useful to someone else, because “I care for them to know”.
(And there, perhaps, lies the truth – “I” care for them to know.)
In reality, we’re shifting some responsibility from our inbox into somebody else’s – we’re passing a monkey:
FYI – it’s your problem now/don’t say I didn’t tell you.
It’s a classic CYA move.
(Okay, perhaps you have good intentions and you genuinely wish to share some key detail inside for someone else’s benefit.)
But let’s not expect the receiver to trawl through the thread to figure out what it is that’s ‘FYI’.
If we sincerely care enough, if there’s a good enough reason for the FYI, the least we can do is to briefly explain the context for their information:
FYI – this is what/why you need to note in the thread below.
(And if there’s not a good enough reason for the FYI, then we’re adding to the unnecessary clutter. And if we’re expecting someone else to do something about something, then our message needs to be something other than an FYI.)