When publishing your research – usually a book or article – with a publisher you usually have to sign a publishing agreement (Copyright Transfer Agreement, CTA). The agreement is basically an exclusive agreement which means that all financial rights are transferred to the publisher and that you as the author are no longer free to use your work as you wish. Unless otherwise agreed you are therefore required to obtain the publisher’s permission if you want to publish your article as part of another work (for example in your PhD dissertation), in other languages, on your own website, or via social media.
Experience has shown that it is worthwhile entering into a dialogue with the publisher regarding amending your agreement to include those rights that you would like to retain.
Model agreements are a proposal for an agreement text, while an author addendum is an addition to a publishing contract. What the two have in common is that they make it easier for the author to negotiate an only partial surrendering of rights to the publisher. In this way you can for example retain the right to republish an article as part of your PhD dissertation, the right to parallel publish your accepted manuscript in Pure, or the right to use the article/book in your own teaching.
The Committee for the Protection of Scientific and Scholarly Work (UBVA) has, together with the Danish Authors’ Society and Danish Publishers, drawn up a model contract (in Danish) which covers both printed and electronic publishing.
There are several other author addenda templates. Sciencecommons.org has created a contract engine with four different author addenda which authors can use. Another option is the SPARC Author Addendum from the Scholarly Publishing and Academic Resources Coalition (SPARC). Finally, there is an Open Access supplementary agreement on parallel publication from Danish foundations.