ISO 18461:2016 specifies rules for the museum community on the collection and reporting of statistics. It provides definitions and counting procedures for all types of resources and services that museums offer to their users. It is recognized that not all measures specified in this International Standard can be collected by museums of different type and size. The aim is to ensure that, where a particular statistic is collected, the same definitions and methods are used. ISO 18461:2016 is not intended to exclude the use of methods not specified in it. There are many different types of museums, with different tasks and audiences, having a range of unique characteristics (structure, funding, governance, etc.), and affected by a number of situational factors. Since there is such a wide variation around the world, it is important to understand that not all methods described in this International Standard may be required by or useful to all museums.