What do the status “NULL”,”PEK NULL”,”PVG NULL” ,”Opening” mean?

Some people searched other websites and get result status of “NULL”,”PEK NULL”,”PVG NULL” or “Opening” etc. Actually those confusing results are errors caused by wrong translation of China Post tracking database.
If You want get more accurate English version tracking result, please track the parcel in following page :
http://track-chinapost.com/startairmail.php .