SEO Indochina is a promoter of Mainland Southeast Asia, aka Indochina, aka the Greater Mekong Subregion.

Mainland Southeast Asia

Mainland Southeast Asia includes the countries of Cambodia, Laos, Myanmar, Thailand and Viet Nam.

Indochina

This group of countries is sometimes included together under the term Indochina, though sometimes this refers only to Viet Nam or to Viet Nam, Laos and Cambodia, for historical reasons. One could use the term Greater Indochina to include those nations wholely on the Asian continent situated between India and China. Interestingly this is a term which is defined by what it is not (neither India nor China).

Greater Mekong Subregion (GMS)

An ASEAN/UN term for the area, and to include Yunnan Province of China (and sometimes Guangxi Province), is the Greater Mekong Subregion (GMS). This is nominally because of the foresight that China would have a dramatic impact on the region based on its increasing use of the Mekong] (Kong River, in China called the Lancang River).