Offprints are individual copies of a paper ordered before publication. Since the price of offprints usually depends on the length of the article writer may not get an exact figure until page proofs are produced. Open Access journals may permit or even encourage writer or their company to print their own copies or to send electronic offprints but check with the journal before assuming that this is allowed as some licences do not permit commercial reuse. It requires members to follow a code of conduct and was involved in developing the 'Principles of transparency and best practice in scholarly publishing' jointly with the Directory of Open Access Journals (DOAJ) and the Committee on Publication Ethics (COPE). Talks given at conferences are called oral presentations. Good preparation is the key to a good talk and also permits co-authors to comment. It is important that ownership of data is clearly set out in the investigators' agreement or publication agreement.