This study investigated the functions of annotations, the role of annotations in markers' decision-making processes, whether annotations conform to conventions, and whether these vary according to subject area. Across subjects a number of scripts were analysed to survey which annotations are subject specific and which are more general. Twelve examiners at different levels of responsibility marked the same General Certificate of Secondary Education Mathematics and Business Studies scripts as one another. The marking was analysed to identify whether there were any patterns in the use of annotations. Retrospective individual interviews were used to inform the analysis of the annotations. Findings showed that the frequency and type of annotations used differed between subjects and that within a subject team examiners drew from a common pool of annotations. Purposes for annotation use included supporting markers' judgements and explaining decisions. (Contains 7 tables.)