or
or
[DOUBLEPOST=1439692615,1439692588][/DOUBLEPOST]as in : ) or : ( or : PEven if you could, they would be difficult to search and platform dependent. My guess is that you would use them for decorative purposes?
And I would say, if it wasn't allowed then YT wouldn't allow it. They'd filter it out, like HTML tags. I actually find it weird they allow it. If every title had emojis, it would be extremely annoying. 
Can you link to a video? I wanna see it now.
Okay, thanks. I see them in black and white, so it's not that annoying.... watch?v=XSkHGtmlK6E
(I find it a bit childish but if it works for your content why not)