" Eb " ... short for Ebony. Black very hard dense wood used for forend tips and grip caps on custom rifles, amongst other things. (also reminds me of a Diana Ross movie character - a model )
Makes training easy - one syllable & doesn't rhyme with sit, stay, come, heel or down. Better still, you can yell it at the top of your lungs in a marsh and no one will laugh at you !
Kind of like the one about the guy who called his Chocolate Lab "Taint"
... cause it 'taint black and it 'taint yellow !!!