When discussing the monetary terms of abdication for the Qing emperors it is important to grasp the importance of the Mexican dollar. In the early 20th century and later 19th century the Mexican dollar or Peso was an internationally recognized currency with an enormous amount of stability and versatility. The Mexican dollar was originally created on an equal exchange to the Spanish dollar or silver bullion which had been a powerful monetary force since the days of the columbian silver and gold expansion. The first issued American federal coins were issued on a basis of 1 US dollar= 1 'Spanish' dollar. The Mexican peso would continue to be amongst the most stable currencies until its devaluation in the 1970s. Other Examples of its use as an international currency include:

1. Their distribution to undercover agents during the world wars for easy conversion over national borders whilst maintaining no trace of home nation's involvements.
2. The Mexican dollar being used in bribery and foreign funding of Chinese Warlords in the revolutionary period.
3. Russian generals in the Russian Civil War issuing pay and receiving foreign funding in Mexican dollars as it was widely accepted in the Vladivostock-Manchuria corridor.
4. Basil Zaharoff and other notable entrepreneurs often used Mexican dollars for clandestine purchases and as the fund of choice for tax havens. The Mexican dollar's stability was primarily derived from its long history and ties to Spanish bullion as well as being more tangibly traced to the once immense Mexican oil industry.

More of course can be said, but this response from /u/thucydideswasawesome is a great starting place!