Most YANG modules and corresponding SIL code are loaded at run-time with the --module and --bundle parameters.
However, there are some YANG modules that are required for RFC conformance or server operation, so they are built into the server code.
| Top-Level Data Node | YANG Module | RFC | Description |
| <modules-state> | ietf-yang-library | RFC 7895 | YANG Module Inventory for the server. Required for YANG conformance information for RESTCONF and all YANG 1.1 modules. |
| <nacm> | ietf-netconf-acm | RFC 6536 | NETCONF Access Control Model (NACM) for all protocols. Required for NACM conformance. Configuration also supported. Enforcement enabled by default. Retrieval for superuser only by default. |
| <netconf> | nc-notifications | RFC 5277 | NETCONF Streams supported by the server for use with <create-subscription>. Required for NETCONF Notifications conformance. |
| <netconf-state> | ietf-netconf-monitoring | RFC 6022 | NETCONF Protocol information. Required for NETCONF Monitoring conformance |
| <restconf-state> | ietf-restconf-monitoring | RFC 8040 | RESTCONF Protocol information. Required for RESTCONF Protocol conformance |
| <system> | yuma-system | Netconf Central | Yuma System Monitoring module. Not required for conformance. This module will be replaced soon by the IETF version in RFC 7317 |