Using numbers in latin representation of Chinese

[skilfautdire]

I'm using from time to time the Babelcarp tea terms translator (off a URL from Yunnansourcing's links) to somewhat gain a bit of insight on Chinese words. Babelcarp uses numbers after the latin representation of each Chinese character. I do not think this is part of pinyin nor wade-giles latin representations. What are these numbers for ? Babelcarp by itself offers no explanation.

Example:

东方美人

Is represented in latin alphabet with:

'Dong1 Fang1 Mei3 Ren2'

Which means:

'Beautiful Eastern Woman'

Which is:

'A heavily oxidized oolong from Fujian or Hsinchu county, Taiwan.'

What are the numbers 1, 1, 3 and 2 for ? I suspect it is to indicated some kind of a pitch in the prononciation but how does it work ?

Babelcarp Chinese Tea Term Translator:

http://www.panix.com/%7eperin/babelcarp.html

[aya_s]

The numbers indeed represent the tones with which you pronounce the syllables/words in Mandarin Chinese.

Mandarin Chinese is a multi-tonal language, meaning a word that has the same phonetic sound (for example, 'ma') has different meanings if you pronounce it with a different tonal inflection. While the words have different Chinese characters to represent them in written language, it can be confusing in Latin characters because we would use the same word to write the Chinese word for 'mother' and 'scold', hence the indication of which tone (and therefore meaning) of the word is indicated by the number.

This page has sound clips of each tone:
http://mandarin.about.com/od/pronunciation/a/tones.htm