Currency formatting and summarization?

Is anyone aware of any valid standards or ISO's for how to best display currency in multiple formats (ex: US dollars and Australia dollars)? I believe this is the only one I could find: iso_4217

Are there any additional ones?

I also cannot find any standards on how to round currencies consistently. For example, it's standard in the US to refer to $50,000 as "$50k", are there any similar standards that can be used for currencies consistently, even in the above US dollars and Australian dollars scenario?