The Vietnam People's Army (Vietnamese: Quân Đội Nhân Dân Việt Nam, variously translated as Vietnamese People's Army and People's Army of Vietnam) has a flag seen here: http://en.wikipedia.org/wiki/File:Flag_of_Viet_Nam_Peoples_Army.svg. (The slogan in Vietnamese translates as "Determined to win"). Esteban Rivera, 6 June 2011
The motto on the hoist translates as "Sure win" or "Certain win" (or "Determined to win" in a more elaborate sense), a reference to the Vietnam War (sic), or "Viet Nam War" (Vietnamese: Chiến tranh Việt Nam), also known as "the Second Indochina War", and also known in Vietnam as Resistance War Against America (Vietnamese: Kháng chiến chống Mỹ) or simply the American War, because of the resolve of North Viet Nam's will to invade the South and unify the country. The Quân Đội Nhân dân Việt Nam, QDND (People's Army of Viet Nam, PAVN) was first conceived in September 1944 at the first Revolutionary Party Military Conference and formally established on 22 December 1944 but its military history traces its roots to 2,000 B.C. Esteban Rivera, 13 February 2016 Sources:https://en.wikipedia.org/wiki/People%27s_Army_of_Vietnam and https://en.wikipedia.org/wiki/Military_history_of_Vietnam
I came across a couple photographs online that show Vietnamese Army unit colors being carried in a parade. The parade took place in Ho Chi Minh City in 2015 for the 40th anniversary of the fall of Saigon (now Ho Chi Minh City) to end the Viet Nam War in 1975. The photograph at http://news.asiaone.com/news/world/vietnam-syndrome-lingers-us shows a number of Vietnamese soldiers carrying Viet Nam People's Army flags with inscriptions and awards on them. The inscriptions are unit designations, printed in yellow beneath the central star. The flag carried at the left front of the group bears the designation "SƯ ĐOÀN VẬN TẢI Ô TÔ 471," which roughly translates as "471st Truck Transportation Division." Additional unit designations are harder to read due to the folds in the flags.
Interestingly, the unit colors also appear to have a number of medals pinned to the flags near the hoist, likely serving the same function as award streamers do on US military colors. Randy Young, 8 July 2016
A photograph at http://img87.imageshack.us/img87/6479/610xrx.jpg [defunct link] appears to show a unit flag of the Vietnamese army, an assumption I based on the number after the writing. It appears different then the image above in having a lot more characters in canton. Marc Pasquin, 13 January 2012
Those more look like state/unit decorations than characters in the canton area. Zachary Harden, 13 January 2012
There's a Vietnamese military (could be Army or Navy/Marine Unit) flag at http://media.lookatvietnam.com/2009/12/images1898873_1.jpg. It which seems to be a military unit based in Trường Sa (also known as the Spratly Islands), from the letters on the obverse of the flag which read "Dao Trường Sa" in yellow capital letters on the bottom right of the flag.
"The Spratly Islands are a group of more than 750 reefs, islets, atolls, cays and islands in the South China Sea between (and claimed by) Vietnam, the Philippines, China, Malaysia and Brunei. About 45 islands are occupied by relatively small numbers of military forces from Vietnam, the People's Republic of China, the Republic of China (Taiwan), Malaysia and the Philippines." Esteban Rivera, 6 June 2011 Source:http://en.wikipedia.org/wiki/Spratly_Islands