[NTG-context] goto

I would like to be able to go directly to a local document by an interaction statement. The \goto command seems to be meant for this. However, the descriptions in the command reference and the Wiki do not explain all of its parameters: In \goto{1}{2}[3] parameters 1 and 2 are marked CONTEXT and 3 is marked REFERENCE. I could find parameter {1} typeset in the text and [3] as the reference in for example a \placefigure. What is {2} supposed to do? \goto{}Something}[] does not places Something to find. I tried to effect the jump to a document on my system with \goto{local-doc}[/Volumes/Users/myhome/Documents/myfigure.jpg] but this does not works as I hoped. How to? Hans van der Meer