The Ironstream package that you download from Precisely Support includes maintenance service, and the package name indicates the service level. For example, the current v2.1 roll-up “SDF21E3” package includes all fixes from the initial version 2.1 GA, SDF2101, up to and including PTF SDF21E3. Additional maintenance should be applied, using the latest fix available. PTFs are viewable and downloadable from the Knowledge Base on Precisely Support and from PDX. All PTFs are cumulative, so by applying the latest you will apply everything else, fixes and enhancements.