Go to read a Memo released on Dec 5, 2006 by USCIS. Title is:
Guidance on Determining Periods of Admission for Aliens Previously in H-4 or L-2 Status; Aliens Applying for Additional Periods of Admission beyond the H-1B Six Year Maximum; and Aliens Who Have Not Exhausted the Six-Year Maximum But Who Have Been Absent from the United States for Over One Year.
Revisions to Adjudicator’s Field Manual (AFM) Chapters 31.2(d), 31.3(g) and 32.6 (AFM Update 06-29)