The General Router ID configuration provides the ability to configure a common Router ID for all routing protocols

ISIS Leaked Route Summarization is a feature which summarizes all the L1 leaked routes in L2 routers. With the help of this L2 LSP size reduces (smaller no of routes in L2 LSP). 

This feature implements support for RFC6232 that helps a user identify source of an LSP purge packet. It can be enabled

Level 1 2 routers set attached bit in their Level 1 LSPs to indicate their reachability to the rest of the network. A

This feature allows user to configure adjacency SID of global scope for IS IS adjacencies. It is an extension to IS IS

Isis 4.21.0F

This feature enables the support of maximum SID depth advertisement by the IS-IS protocol in its LSPDB as defined in RFC8491, with this feature adding support for one type of MSD: Base MPLS Imposition (BMI-MSD).

When there are multiple VRFs on the device and there is a need to share routes between them, typically for shared

VRF Route leaking can be used when routes from one VRF are required in another VRF (e.g. in case of shared services). If VrfLeak Agent is being used to leak routes, the leaked routes (in destination VRF) can be redistributed into IGPs.

Routing Control Functions (RCF) is a language that can express route filtering and attribute modification logic in a powerful and programmatic fashion.The document covers: Configurations of a RCF function for BGP points of application

This feature adds support for configuring multiple authentication keys each with a specified lifetime using a shared secret profile. With a shared secret profile, a current key (key having the most recent start time) is automatically picked as per the lifetime specified. Authentication types supported are MD5 and SHA. The feature can be configured at both global and interface level. SHA algorithms supported are SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512.

Configuring the IGP cost for tunnels is a feature that allows influencing the BGP best path selection for routes

BGP LDP Isis 4.22.1F