Version 1.0 is the initial proposal. Version 1.1 consolidates ID attributes. Version 1.2 adds the ID and cost extensions. Version 1.3 changes the attribute keys changed from xs:Name to xs:token (to allow for spaces in the keys). Version 1.4 allows classifier keys to be grouped by single quotes (to be able to handle attribute keys with spaces in classifiers). As from Version 2.0 allows empty logs and empty traces, and introduces list and container attributes.

When referring to the First XES Standard, please refer to: