Here’s some information I’ve pieced together from various sources about symbolism and history of the Tibetan National flag:
“1. The white snow mountain in the center depicts the land of the great nation of Tibet.
2. The six red rays emanating from the sun symbolize the six original peoples of Tibet: the Se, My, Dong, Tong, Dru, and Ra.
3. The blue rays symbolize the commitment to spiritual and secular rule.
4. The pair of snow-lions symbolize the complete victory of the spiritual and secular ruling government
5. The three-sided yellow border represents the spread and flourishing of the Buddha’s purified gold-like teachings in all directions and times. The side without a border represents Tibet’s openness to non-Buddhist thought.
6. The raised jewel symbolizes Tibet’s reverence for the three Precious Gems; the Buddha, the Dharma, and the Sangha.” (Int’l Campaign for Tibet)
7.”The two coloured swirling jewel held between the two lions represents the peoples’ guarding and cherishing the self discipline of correct ethical behaviour, principally represented by the practices of the ten exalted virtues and the 16 humane modes of conduct. The swirling jewel coincidentally shares some appearance resemblance with the yin and yang symbol from Taoism.” (Tibet.com)
The flag of Tibet was reintroduced in 1912 by the 13th Dalai Lama, who united the army flags of various provinces to design the present one. Since then, it served as the all-Tibet military flag until 1950.” (Wikipedia: A Tibetan revolutionary : the political life and times of Bapa Phuntso Wangye)
“During the era between 9th and 18th century, Tibet did not have an official army. In late 18th century, after the Qing government defended Tibet from the Nepalese invasion, they created a twenty-nine points resolution called “Twenty-Nine Regulations for Better Government in Tibet”. The fourth clause of this decree stated “The lack of official military in the region of Tibet has led to emergency drafts in time of crisis, which has proven to be harmful to the Tibetan people. (This reform package included the selection of top incarnations (hutuktus) like the Dalai and Panchen Lamas through a lottery conducted in a golden urn, the aim being to prevent the selection of incarnations being manipulated to fall in politically powerful lay families.) The emperor has approved for Tibet to form a official troop of three thousand men. One thousand each will be stationed in front and back Tibet, five hundred in Shigatse and five hundred in Dingri.” These three thousand troops became what is commonly known as the Tibetan Infantry. Considering that a military flag is a necessity for the daily training of this army, the central Qing government approved the “snow lion flag” as official military flag of Tibet.
This tradition is continued down to present day, where the Tibetan government in exile still uses the “snow lion flag” as their official representation.” (Wikipedia: Goldstein, Melvyn C. “The Snow Lion and the Dragon”. University of California Press, 1997. Pg. 19)
“The Tibetan national flag is intimately connected with the authentic history and royal lineages of Tibet which are thousands of years old. Furthermore, in the Tibetan Royal year 820 or in the seventh century of the Christian era, at the time of the Tibetan religious King Song-Tsen Gamp the Great extensive land of Tibet was divided into large and small districts known as “gö-kyi tong-de” and “yung-g’i mi-de”. From these large and small districts, an army of 2,860,000 men was chosen and stationed along the borders of Tibet, and the subjects thus lived in safety. The bravery and heroism of the Tibetan people at that time in conquering and ruling even the adjacent empire of China is well-known in world history.
“At that time, it is recorded that the regiment of Yö-ru tö had a military flag with a pair of snow-lions facing each other; that Yä-ru mä had a snow-lion with a bright upper border; that of Tsang Rulag, had a snow-lion standing upright, springing towards the sky; and the flag of ü-ru tö had a white flame against a red background, and so forth. In this way. the regiments of each area had its own individual military standard. Continuing with that tradition up to the beginning of the twentieth century, various regiments within the Tibetan army have had military flags with either a pair of snow-lions facing each other, or a snow-lion springing upwards and so forth.
“In the latter part of this period, during the rule of His Holiness the Great Thirteenth Dalai Lama, this eminent spiritual and temporal ruler of Tibet enacted many modifications in administrative policies in accordance with international customs. Based on the formats of previous Tibetan military flags, His Holiness improved upon them and designed the present, modern national flag. With an official proclamation, He declared that this would be the uniform, standard flag to be adopted by all Tibetan military defence establishments. Since the time of that proclamation, all Tibetan regiments have likewise adopted this flag as their standard.
“The colour scheme of the Tibetan national flag gives a clear indication of all aspects of Tibet in its symbolism such as the geographic features of the religious. snowy land of Tibet, the customs and traditions of Tibetan society, the political administration of the Tibetan government and so forth.
“History attests to the fact that Tibet is one of the most ancient nations of the world. Therefore, in all the three regions of Tibet, irrespective of caste and creed, this national flag inherited from our ancestors is universally accepted as a common, peerless treasure and even today still continues to be highly respected and esteemed as in the past.” (TGIE, http://www.tibet.com)