Authors, associate your questions with tags for the purpose of identification i.e. metadata that helps describe the question. Tag your items by subject, strand, topic, age, key stage, attainment target or keyword(s). Add tags that are proprietary to your own publishing model.
Tagging empowers your item bank, allowing questions to be found by searching the database and enabling the rapid building of custom tests. Search and filter by any combination of tags/keywords then simply choose the questions you want to include in your custom test from a pick list.