In nasm, pseudo-instructions like db can be used to declare initialized data. For example:
db 0, 1
Declares two bytes of initialized data, a 0 followed by a 1.
There are more types beyond db. The documentation says:
DB, DW, DD, DQ, DT, DO, DY and DZ (collectively "Dx" in this documentation) are used, much as in MASM, to declare initialized data in the output file. They can be invoked in a wide range of ways: ... DT, DO, DY and DZ do not accept integer numeric constants as operands.
However, it doesn't give examples of DY adn DZ use for initialized data.
Let's say I just want to declare a zmm register's worth of 0 bytes (64 bytes). How do I do it? As the documentation says "DT, DO, DY and DZ do not accept integer numeric constants as operands.", so dz 0 doesn't work, but it isn't clear what forms they do accept.