Cisco IOS XE supports the Yet Another Next Generation (YANG) data modeling language. YANG can be used with the Network Configuration Protocol (NETCONF) to provide the desired solution of automated and programmable network operations. NETCONF(RFC6241) is an XML-based protocol that client applications use to request information from and make configuration changes to the device. YANG is primarily used to model the configuration and state data used by NETCONF operations. Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16- 5/configuration_guide/prog/b_165_prog_9500_cg/data_models.pdf Note: Although NETCONF also uses XML but XML is not a data modeling language.