In many disciplines the position of last author is endowed with special status and may be competed over almost as fiercely as the first. In some cases, the corresponding author or guarantor occupies the last position but, again, there is no rule about this. The only rule in deciding who goes last (or first) is to discover all authors' understandings and expectations and to try to agree this as amicably as possible. Submission deadlines are sometimes so long in advance of major conferences that there is a danger that only rather old research gets presented. Lead time is the time between acceptance and publication. Most journals publish accepted articles on their websites before they appear in print. Journals publish two distinct types of letters: those that comment on published material, and those that contain new research findings. If the publication stimulates letters that the journal plans to publish the author will normally be given the opportunity to respond.