The flag that is arguably most visible at the closing Mass of WYD isn't even an official flag of a nation, but one that is said to be banned in its home country.

The yellow flag with three horizontal red lines is the former SouthVietnamese flag known as the Vietnamese Heritage or Freedom Flag.

With this flag we are reminded of those around the world who areoppressed and have their human rites violated and of governments whooppress the free practice of religion and speech in their nations.

About the flag;
“At the present time. there are absolutely no freedom and no democracyof any kinds in Vietnam. Human rights are seriously abused by theVietnamese communist regime.

During the course of fighting for freedom, democracy, and humanrights of the people in Vietnam, we must have our whole-hearted supportto maintain and wave high this National Flag of Free Vietnam until thefreedom, democracy, and human rights are finally realized in Vietnam.That is why, each time seeing the Free Vietnam National Flag, themajority of freedom-democracy-loving Vietnamese, in Vietnam as well asaround the world, feel as if they saw the nation's savior.”

From http://www5.brinkster.com/vla/pkt1.asp

In the United States, at least 11 states and 113 cities have adoptedresolutions recognizing the former South Vietnamese flag as theVietnamese Heritage and Freedom Flag.