Originally Posted by moondog

At the risk of getting off topic, the 48 hour visa waiver program, which was launched in Shanghai circa 2002, was replaced by 72 hour TWOV in 2012, and includes a growing list of eligible cities, but shorter list of eligible passports. (The link you pulled is from 2008, and things change fast over here.)

Basic (24 hour) TWOV hasn't changed in a material way since its inception. The one exception that comes to mind is the removal of the "without leaving the airport" clause, but this was rarely enforced in the first place. In fact, when the policy was first launched, it was impossible to transit in any Chinese airports without "leaving" them. This is still largely the case today.