In table A2 of Intel® 64 and IA-32 Architectures Software Developer’s Manual Volume 2; Bound is 0x62 Gv, Ma. G means operand 1 will be interpreted as a general purpose register. M means operand 2 must be a memory operand. Meaning the mod field must not be 0b11. I then assume that other mod field values will be interpreted as the second byte of EVEX prefix; and 0x62 will be interpreted as EVEX prefix header.