LO meaning in Regional ?

Lao, sometimes referred to as Laotian (ລາວ, [láːw] 'Lao' or ພາສາລາວ, [pʰáːsǎːláːw] 'Lao language'), is a Kra–Dai language of the Lao people. It is spoken in Laos, where it is the official language for around 7 million people, as well as in northeast Thailand, where it is used by around 23 million people, usually referred to as Isan. Lao serves as a lingua franca among the citizens of Laos, who also speak approximately 90 other languages, many of which are unrelated to Lao.

It is a tonal and analytic language, similar to other Kra-Dai languages as well as to Chinese and Vietnamese. Spoken Lao is mutually intelligible with Thai and Isan, fellow Southwestern Tai languages, to such a degree that their speakers are able to effectively communicate with one another speaking their respective languages. These languages are written with slightly different scripts but are linguistically similar and effectively form a dialect continuum.

Although there is no official standard, the Vientiane dialect became the de facto standard language in Lao PDR, and the Khonkaen dialect became the de facto standard language in Isan in the second half of the 20th century.