http://www.ibm.com/developerworks/linux/library/l-gas-nasm.html
last line read: NASM uses the resb, resw, and resd keywords to allocated byte, word, and dword space in the BSS section.
(back in dec/jan or so, I was trying to learn some asm using examples in GAS and the NASM manual; wish I had time to restart those studies!)