In addition, Waghhh is also written on Waghhh Banners to increase Ork morale.
Search for "Ork Slangs" on urbandictionay.com for more.
Also see Boyz, Ork, Gorkamorka, Dakka, Tankbusta,Shoota,Choppaz, Warboss, Big Mek, Nobz, Grot and gretchin,
Big Mek : Let me give ya' a thumb! Thos' are grethins!