Just applied for a Non O volunteer visa in Hanoi Vietnam, at the Thai Embassy. As well as all the listed documents you need to provided, I was also asked for a copy of House book (Blue book) for where I live in Thailand and a copy of a rental bill, this was not noted anywhere. I had my rental contract and Landlords ID (copy) signed and dated. When I asked and explained this was not on the website, the lady said yes it has not been updated on the website. Hope this helps.