D logo copyright

[Alix Pexton via Digitalmars-d]

On 18/07/2014 4:03 PM, "Ola Fosheim Grøstad" 
<ola.fosheim.grostad+dlang at gmail.com>" wrote:

>> This may allow for the creation of a new graphic that is a derivative
>> work of the current one but has a copyright held by Digital Mars.
>
> No. The copyright will be held by BOTH the original author and the
> author of the derivative work, it is joint ownership and you need the
> permission of two authors instead of one.

This is contrary to my understanding from what I have read (although my 
research has been biased towards the UK due to google knowing where I 
live), can you provide citations that support this?

A...