Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for classifying changes to resources. In one aspect, a method includes obtaining a first version of a resource. The method includes obtaining a second version of the resource, the second version representing a change to the first version of the resource. The method includes determining feature data that describes changes from the first version to the second version. The method includes creating a feature vector from the feature data. The method includes providing the feature vector to a support vector machine, the support vector machine trained to classify the second version of the resource as having one of changes requiring a change notification or changes not requiring a change notification. The method includes classifying the second version as requiring a change notification or not requiring a change notification based on output from the support vector machine.