z/OS XML System Services provides the ability for parsing operations to be run on specialty processors: an IBM® System z® Application Assist Processor (zAAP) or an IBM System z10™ Integrated Information Processor (zIIP). The z/OS XML parser, when running in TCB mode, is eligible to run on a zAAP, in environments in which one or more zAAPs are configured. The z/OS® XML parser, when running in enclave SRB mode, is eligible to run on a zIIP processor, in environments where one or more zIIPs are configured. Ancillary z/OS XML System Services, such as the query service and the control service, as well as the StringID exit and memory management exits, are not eligible to run on specialty processors. Running of z/OS XML System Services parsing operations on a specialty processor occurs transparently to the calling application.