Ⰹⰵⱄⱅⰵ ⰾⰻ ⰸⱀⰰⰾⰻ ⰴⰰ ⰳⰾⰰⰳⱁⰾⰻⱌⰰ ⰻⰿⰰ ⱄⰲⱁⰹ Unicode ⱄⰵⰳⰿⰵⱀⱅ?
That thing says "Did you know that glagolitic script has its own Unicode segment?" To read it, you may need font called Dilyan.
However the title says "Glagolitic Unicode does not have letter J". Letter J looks like combined HP (oh yes, don't start). That's amazing. In the glagolitic transliterator I designed some time ago, I've replaced it with letter iže – Ⰹ – which seems to serve the same purpose. Incredibly, Wikipedia article also does not mention J.
But the oversight looks stunning to me. Especially since you can't reproduce it graphically using other symbols, and it's perfect for transliteration.
(Note, my transliterator matches mostly letter-for-letter and therefore may be flawed. I do think it's quite faithful though.)