A device may be configured to perform filtering based on information included in a neural network post-filter characteristics message. In one example, the neural network post-filter characteristics message includes a syntax element indicating a purpose of a post-processing filter and a syntax element specifying whether syntax elements related to a purpose, input formatting, output formatting, and complexity of the post-processing filter are present in the neural network post-filter characteristics message. The syntax element indicating a purpose may precede the syntax element specifying whether syntax elements are present.