Educators set restrictions in examinations to enable them to assess learning outcomes under particular conditions. The open book versus closed book binary is an example of the sorts of restrictions examiners have traditionally set. In the late 2000s this was expanded to a trinary to include open web examinations. However, the current technology environment, particularly for online examinations, makes this trinary not particularly useful. The web now includes generative artificial intelligence tools, and contract cheating sites, both of which are capable of completing examination questions within the examination period. Closed book, open book and open web no longer offers enough clarity or specificity when communicating examination restrictions. This article proposes a new taxonomy of restrictions for examinations, with a particular focus on online examinations. The taxonomy consists of three dimensions: information, people and tools. The paper explores the possible settings for those dimensions. Five criteria are provided to help examination designers in selecting restrictions: the learning outcomes being assessed; the feasibility of restrictions; consequential validity; authenticity; and values. Taken together, this taxonomy and the criteria provide ways of thinking about restrictions in examinations that can prompt educators towards examination designs that are more valid and robust against cheating.