9-bit rotation to the left. the register's bits are shifted left. The carry value is put into 0th bit of the register, and the leaving 7th bit is put into the carry.
RL A RL B RL C RL D RL H RL L RL (HL) RL (IX+n) RL (IY+n)
C is changed to the leaving 7th bit, H and N are reset, P/V is parity, S and Z are modified by definition.
r denotes 8-bit register.