Travel to China: Re-Entry Permit for greencard

Thanks ca981!

While searching online. I found this file (appears to be from uscis official website) is saying that green card holders can stay outside US for l year. I knew it was 6 months before. Is this a change of US Immigration Policy, or I misunderstood it here? Below is the doc that I found for RE-ENTRY PERMIT.

Thanks again !!!


http://www.uscis.gov/sites/default/files/USCIS/Resources/B5en.pdf :

What if I must leave the United States before I can file a
Form I-131 for a reentry permit?
You do not need a reentry permit if you will be outside the United
States for less than 1 year. If you have been outside the United
States for less than 1 year, you may use your Permanent Resident
Card (Form I-551) as your travel document.