Hi,
I'm refering to this article:
https://support.apple.com/en-us/HT202796
But isn't it possible to install OS X on an external volume using the recovery partition? For e.g. I already have Yosemite installed (and also it's recovery partition - got the Mac last december), isn't it possible to just boot up it's recovery partition and install on the usb drive from there?
Kind regards,
Michael