回複：but i seems that the spirit of the 2006 Aytes memo

only says H1 is subject to 6 years limitation?
-Not true. H1 has six-year limitation and H4 has it also. So, one person can has h1 for six years plus h4 six years, and total 12 years of H1 plus h4.

But if H1 holder extends his/her H1 status beyond the six years limitation, the H4 holder also can extend his/her H4 status with the H1 hodler beyond six years.