How do you write a byte to a memory location? I've tried various idioms to reference a memory address in MOV but it rejects them all.
This syntax is intentionally verbose, so anyone new to assembly wouldn't mistakenly store word when byte was intended.
You can also check the complete supported syntax here : https://yjdoc2.github.io/8086-emulator-web/help in data transfer, mov section.
Hope this helps!