In the SDM rev. 48, vol. 2A, page 3-546, in the description of the exceptions for the MOVNTI instruction in the real-mode, it is specified that the instruction can generate
#GP If a memory operand is not aligned on a 16-byte boundary, regardless of segment.
There is no exceptions specified for unaligned stores for protected or long mode, except for AC enabled. AMD reference is also silent about the unaligned stores. Is this indeed an irregularity in real mode, or just a typo in the spec ?