REST API for attaching files to issues

Hi,
I am trying to attach files to an issue using the REST API. Alas, the page of importance is missing some useful information. See:

https://confluence.jetbrains.com/display/YTD6/Attach+File+to+an+Issue

The example doesn't actually show the file being sent via the API. The documentation suggest there is a files tag, but it doesn't state what format that would be. Is it a space, comma, semi-colon separated list for example.

I am no web guru so have no idea if there are any accepted precedents for this. The example suggests that flag.png is uploaded, but the example syntax shows:

http://localhost:8081/rest/issue/CMN-1917/attachment?authorLogin=gorbachev&created=1149678852000

Where is flag.png in that lot?

Kind regards