BBB

The full meaning on that abbreviation is "Big Black Bruh". It got popular after Dankus Memecus said it several times during his streams on HoI4. Actually, there is a point of view, that he was just stammering with the first "b"-letter, which created an effect of "b-b-bruh" that then transformed into BBB

*your teammates losing 8 tanks in one encirclement*
you: bbb

man alta

english variation of the german words "mann alter", which stands for "dude"/"oooh man"
just a quick way to express how disappointed u are

friend: bro seems like we are losing

you: oooh man alta