Copyright Colour Codes

A huge amount of material is offered through Deltaworks Online. Every media item has its own copyright colour code. These colour codes allow you to identify quickly and easily which pieces of material can be reused freely and which cannot. The 4 different colour codes are explained below.


All material found on the website with a green colour code can be reused freely for non-profitable purposes. It is open-content. Of course, we hope you will include a link back to Deltaworks Online.


Using this material for non-profitable purposes is allowed only if you cite the source next to the photo. Furthermore we hope you can put a link Deltaworks Online.


The use of this material is prohibited. If you wish to use it, we can refer you to the authors with whom you can make an arrangement regarding the use.

 Question mark

With regards to some photos it is unclear who took them (i.e. photos of the 1953 floods). There are no records in the archives. As these photos are very important to the project we have included them nevertheless. If you know who took them, please let us know so we can add the correct acknowledgements to the photo.