Section 11.4 of the Guide outlines in a very rudimentary way how to handle multi-currency situations. The language is quite informal, and there are areas that need improvement. Specifically:

* Discussion of the importance of currency choice for accounts is buried at the very bottom of the section.
* Discussion and guidance is scant for situations where the user has ongoing need for multi-currency support (e.g. a user who regularly uses both GBP and EUR in their file).
* Description of Gnucash's built-in currency exchange features is missing.
* Examples of colloquialisms: "You find the boat, and since it's a bargain..." "(After all, the 2008 Olympics in Beijing have finished and the price has returned to Earth)" 

I recommend a moderate rewrite.