diff --git a/docs/admin/auth-server/oauth-features/README.md b/docs/admin/auth-server/oauth-features/README.md
index a85e93acc99..2bf21faa291 100644
--- a/docs/admin/auth-server/oauth-features/README.md
+++ b/docs/admin/auth-server/oauth-features/README.md
@@ -28,6 +28,7 @@ The [Janssen Authentication Server](https://github.com/JanssenProject/jans/tree/
 - JWT Secured Authorization Response Mode for OAuth 2.0 (JARM) [(spec)](https://openid.net/specs/oauth-v2-jarm.html)
 - OAuth 2.0 for First-Party Native Applications [(spec draft)](https://www.ietf.org/archive/id/draft-parecki-oauth-first-party-native-apps-00.html)
 - The Use of Attestation in OAuth 2.0 Dynamic Client Registration [(spec draft)](https://www.ietf.org/id/draft-tschofenig-oauth-attested-dclient-reg-00.html)
+- OpenID Connect Core Error Code unmet_authentication_requirements [(spec)](https://openid.net/specs/openid-connect-unmet-authentication-requirements-1_0.html)
 
 
 ## Protocol Overview
diff --git a/docs/admin/auth-server/openid-features/acrs.md b/docs/admin/auth-server/openid-features/acrs.md
index 845396f5f72..55decb47e85 100644
--- a/docs/admin/auth-server/openid-features/acrs.md
+++ b/docs/admin/auth-server/openid-features/acrs.md
@@ -125,6 +125,14 @@ flowchart TD
   to any reason, then the Janssen Server uses the [internal server ACR](#1-internal-janssen-server-acr) to authenticate
   the end-user.
 
+## Errors 
+
+### unmet_authentication_requirements
+
+If authorization request is sent to Authorization Endpoint with `acr_values` for which 
+AS it not able to find "Person Authentication" custom script, it returns "unmet_authentication_requirements"
+with detail log in `jans-auth.log`.
+
 ## Want to contribute?
 
 If you have content you'd like to contribute to this page in the meantime, you can get started with our [Contribution guide](https://docs.jans.io/head/CONTRIBUTING/).