diff --git a/Cargo.lock b/Cargo.lock
index 158e5921..dc5cb59e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1548,6 +1548,7 @@ version = "0.1.0"
 dependencies = [
  "chrono",
  "crc",
+ "mas-iana",
  "oauth2-types",
  "rand",
  "serde",
@@ -1670,6 +1671,7 @@ dependencies = [
  "argon2",
  "chrono",
  "mas-data-model",
+ "mas-iana",
  "oauth2-types",
  "password-hash",
  "rand",
@@ -1729,6 +1731,7 @@ dependencies = [
  "hyper",
  "mas-config",
  "mas-data-model",
+ "mas-iana",
  "mas-jose",
  "mas-storage",
  "mas-templates",
diff --git a/crates/data-model/Cargo.toml b/crates/data-model/Cargo.toml
index e9b684f0..1215198a 100644
--- a/crates/data-model/Cargo.toml
+++ b/crates/data-model/Cargo.toml
@@ -13,4 +13,5 @@ url = { version = "2.2.2", features = ["serde"] }
 crc = "2.1.0"
 rand = "0.8.4"
 
+mas-iana = { path = "../iana" }
 oauth2-types = { path = "../oauth2-types" }
diff --git a/crates/data-model/src/oauth2/authorization_grant.rs b/crates/data-model/src/oauth2/authorization_grant.rs
index a7ccf1f2..7cffc4e3 100644
--- a/crates/data-model/src/oauth2/authorization_grant.rs
+++ b/crates/data-model/src/oauth2/authorization_grant.rs
@@ -15,7 +15,8 @@
 use std::num::NonZeroU32;
 
 use chrono::{DateTime, Duration, Utc};
-use oauth2_types::{pkce::CodeChallengeMethod, requests::ResponseMode};
+use mas_iana::oauth::PkceCodeChallengeMethod;
+use oauth2_types::{pkce::CodeChallengeMethodExt, requests::ResponseMode};
 use serde::Serialize;
 use thiserror::Error;
 use url::Url;
@@ -25,13 +26,13 @@ use crate::{traits::StorageBackend, StorageBackendMarker};
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize)]
 pub struct Pkce {
-    pub challenge_method: CodeChallengeMethod,
+    pub challenge_method: PkceCodeChallengeMethod,
     pub challenge: String,
 }
 
 impl Pkce {
     #[must_use]
-    pub fn new(challenge_method: CodeChallengeMethod, challenge: String) -> Self {
+    pub fn new(challenge_method: PkceCodeChallengeMethod, challenge: String) -> Self {
         Pkce {
             challenge_method,
             challenge,
diff --git a/crates/data-model/src/tokens.rs b/crates/data-model/src/tokens.rs
index d65abeef..2932e4f2 100644
--- a/crates/data-model/src/tokens.rs
+++ b/crates/data-model/src/tokens.rs
@@ -14,7 +14,7 @@
 
 use chrono::{DateTime, Duration, Utc};
 use crc::{Crc, CRC_32_ISO_HDLC};
-use oauth2_types::requests::TokenTypeHint;
+use mas_iana::oauth::OAuthTokenTypeHint;
 use rand::{distributions::Alphanumeric, Rng};
 use thiserror::Error;
 
@@ -159,12 +159,12 @@ impl TokenType {
     }
 }
 
-impl PartialEq<TokenTypeHint> for TokenType {
-    fn eq(&self, other: &TokenTypeHint) -> bool {
+impl PartialEq<OAuthTokenTypeHint> for TokenType {
+    fn eq(&self, other: &OAuthTokenTypeHint) -> bool {
         matches!(
             (self, other),
-            (TokenType::AccessToken, TokenTypeHint::AccessToken)
-                | (TokenType::RefreshToken, TokenTypeHint::RefreshToken)
+            (TokenType::AccessToken, OAuthTokenTypeHint::AccessToken)
+                | (TokenType::RefreshToken, OAuthTokenTypeHint::RefreshToken)
         )
     }
 }
diff --git a/crates/handlers/src/oauth2/authorization.rs b/crates/handlers/src/oauth2/authorization.rs
index 7c658335..52b10801 100644
--- a/crates/handlers/src/oauth2/authorization.rs
+++ b/crates/handlers/src/oauth2/authorization.rs
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::collections::{HashMap, HashSet};
+use std::collections::HashMap;
 
 use chrono::Duration;
 use hyper::{
@@ -25,6 +25,7 @@ use mas_data_model::{
     Authentication, AuthorizationCode, AuthorizationGrant, AuthorizationGrantStage, BrowserSession,
     Pkce, StorageBackend, TokenType,
 };
+use mas_iana::oauth::OAuthAuthorizationEndpointResponseType;
 use mas_storage::{
     oauth2::{
         access_token::add_access_token,
@@ -50,9 +51,9 @@ use oauth2_types::{
         RegistrationNotSupported, RequestNotSupported, RequestUriNotSupported,
     },
     pkce,
+    prelude::*,
     requests::{
         AccessTokenResponse, AuthorizationRequest, AuthorizationResponse, Prompt, ResponseMode,
-        ResponseType,
     },
     scope::ScopeToken,
 };
@@ -191,16 +192,15 @@ struct Params {
 /// figure out what response mode must be used, and emit an error if the
 /// suggested response mode isn't allowed for the given response types.
 fn resolve_response_mode(
-    response_type: &HashSet<ResponseType>,
+    response_type: OAuthAuthorizationEndpointResponseType,
     suggested_response_mode: Option<ResponseMode>,
 ) -> anyhow::Result<ResponseMode> {
     use ResponseMode as M;
-    use ResponseType as T;
 
     // If the response type includes either "token" or "id_token", the default
     // response mode is "fragment" and the response mode "query" must not be
     // used
-    if response_type.contains(&T::Token) || response_type.contains(&T::IdToken) {
+    if response_type.has_token() || response_type.has_id_token() {
         match suggested_response_mode {
             None => Ok(M::Fragment),
             Some(M::Query) => Err(anyhow::anyhow!("invalid response mode")),
@@ -345,11 +345,11 @@ async fn get(
     let redirect_uri = client
         .resolve_redirect_uri(&params.auth.redirect_uri)
         .wrap_error()?;
-    let response_type = &params.auth.response_type;
+    let response_type = params.auth.response_type;
     let response_mode =
         resolve_response_mode(response_type, params.auth.response_mode).wrap_error()?;
 
-    let code: Option<AuthorizationCode> = if response_type.contains(&ResponseType::Code) {
+    let code: Option<AuthorizationCode> = if response_type.has_code() {
         // 32 random alphanumeric characters, about 190bit of entropy
         let code: String = thread_rng()
             .sample_iter(&Alphanumeric)
@@ -400,8 +400,8 @@ async fn get(
         params.auth.max_age,
         None,
         response_mode,
-        response_type.contains(&ResponseType::Token),
-        response_type.contains(&ResponseType::IdToken),
+        response_type.has_token(),
+        response_type.has_id_token(),
     )
     .await
     .wrap_error()?;
diff --git a/crates/handlers/src/oauth2/discovery.rs b/crates/handlers/src/oauth2/discovery.rs
index 87b7bb40..45e0597b 100644
--- a/crates/handlers/src/oauth2/discovery.rs
+++ b/crates/handlers/src/oauth2/discovery.rs
@@ -15,12 +15,17 @@
 use std::collections::HashSet;
 
 use mas_config::OAuth2Config;
-use mas_iana::jose::JsonWebSignatureAlg;
+use mas_iana::{
+    jose::JsonWebSignatureAlg,
+    oauth::{
+        OAuthAuthorizationEndpointResponseType, OAuthClientAuthenticationMethod,
+        PkceCodeChallengeMethod,
+    },
+};
 use mas_jose::SigningKeystore;
 use oauth2_types::{
     oidc::{ClaimType, Metadata, SubjectType},
-    pkce::CodeChallengeMethod,
-    requests::{ClientAuthenticationMethod, Display, GrantType, ResponseMode},
+    requests::{Display, GrantType, ResponseMode},
 };
 use warp::{filters::BoxedFilter, Filter, Reply};
 
@@ -34,11 +39,11 @@ pub(super) fn filter(
     // This is how clients can authenticate
     let client_auth_methods_supported = Some({
         let mut s = HashSet::new();
-        s.insert(ClientAuthenticationMethod::ClientSecretBasic);
-        s.insert(ClientAuthenticationMethod::ClientSecretPost);
-        s.insert(ClientAuthenticationMethod::ClientSecretJwt);
-        s.insert(ClientAuthenticationMethod::PrivateKeyJwt);
-        s.insert(ClientAuthenticationMethod::None);
+        s.insert(OAuthClientAuthenticationMethod::ClientSecretBasic);
+        s.insert(OAuthClientAuthenticationMethod::ClientSecretPost);
+        s.insert(OAuthClientAuthenticationMethod::ClientSecretJwt);
+        s.insert(OAuthClientAuthenticationMethod::PrivateKeyJwt);
+        s.insert(OAuthClientAuthenticationMethod::None);
         s
     });
 
@@ -72,13 +77,13 @@ pub(super) fn filter(
 
     let response_types_supported = Some({
         let mut s = HashSet::new();
-        s.insert("code".to_string());
-        s.insert("token".to_string());
-        s.insert("id_token".to_string());
-        s.insert("code token".to_string());
-        s.insert("code id_token".to_string());
-        s.insert("token id_token".to_string());
-        s.insert("code token id_token".to_string());
+        s.insert(OAuthAuthorizationEndpointResponseType::Code);
+        s.insert(OAuthAuthorizationEndpointResponseType::Token);
+        s.insert(OAuthAuthorizationEndpointResponseType::IdToken);
+        s.insert(OAuthAuthorizationEndpointResponseType::CodeToken);
+        s.insert(OAuthAuthorizationEndpointResponseType::CodeIdToken);
+        s.insert(OAuthAuthorizationEndpointResponseType::IdTokenToken);
+        s.insert(OAuthAuthorizationEndpointResponseType::CodeIdToken);
         s
     });
 
@@ -107,8 +112,8 @@ pub(super) fn filter(
 
     let code_challenge_methods_supported = Some({
         let mut s = HashSet::new();
-        s.insert(CodeChallengeMethod::Plain);
-        s.insert(CodeChallengeMethod::S256);
+        s.insert(PkceCodeChallengeMethod::Plain);
+        s.insert(PkceCodeChallengeMethod::S256);
         s
     });
 
diff --git a/crates/handlers/src/oauth2/introspection.rs b/crates/handlers/src/oauth2/introspection.rs
index 8a043b6d..4dda8634 100644
--- a/crates/handlers/src/oauth2/introspection.rs
+++ b/crates/handlers/src/oauth2/introspection.rs
@@ -14,6 +14,7 @@
 
 use mas_config::{OAuth2ClientConfig, OAuth2Config};
 use mas_data_model::TokenType;
+use mas_iana::oauth::{OAuthClientAuthenticationMethod, OAuthTokenTypeHint};
 use mas_storage::oauth2::{
     access_token::lookup_active_access_token, refresh_token::lookup_active_refresh_token,
 };
@@ -21,9 +22,7 @@ use mas_warp_utils::{
     errors::WrapError,
     filters::{client::client_authentication, database::connection},
 };
-use oauth2_types::requests::{
-    ClientAuthenticationMethod, IntrospectionRequest, IntrospectionResponse, TokenTypeHint,
-};
+use oauth2_types::requests::{IntrospectionRequest, IntrospectionResponse};
 use sqlx::{pool::PoolConnection, PgPool, Postgres};
 use tracing::{info, warn};
 use warp::{filters::BoxedFilter, Filter, Rejection, Reply};
@@ -64,12 +63,12 @@ const INACTIVE: IntrospectionResponse = IntrospectionResponse {
 
 async fn introspect(
     mut conn: PoolConnection<Postgres>,
-    auth: ClientAuthenticationMethod,
+    auth: OAuthClientAuthenticationMethod,
     client: OAuth2ClientConfig,
     params: IntrospectionRequest,
 ) -> Result<Box<dyn Reply>, Rejection> {
     // Token introspection is only allowed by confidential clients
-    if auth.public() {
+    if auth == OAuthClientAuthenticationMethod::None {
         warn!(?client, "Client tried to introspect");
         // TODO: have a nice error here
         return Ok(Box::new(warp::reply::json(&INACTIVE)));
@@ -96,7 +95,7 @@ async fn introspect(
                 scope: Some(session.scope),
                 client_id: Some(session.client.client_id),
                 username: Some(session.browser_session.user.username),
-                token_type: Some(TokenTypeHint::AccessToken),
+                token_type: Some(OAuthTokenTypeHint::AccessToken),
                 exp: Some(exp),
                 iat: Some(token.created_at),
                 nbf: Some(token.created_at),
@@ -116,7 +115,7 @@ async fn introspect(
                 scope: Some(session.scope),
                 client_id: Some(session.client.client_id),
                 username: Some(session.browser_session.user.username),
-                token_type: Some(TokenTypeHint::RefreshToken),
+                token_type: Some(OAuthTokenTypeHint::RefreshToken),
                 exp: None,
                 iat: Some(token.created_at),
                 nbf: Some(token.created_at),
diff --git a/crates/handlers/src/oauth2/token.rs b/crates/handlers/src/oauth2/token.rs
index 128798e5..0d9f4b30 100644
--- a/crates/handlers/src/oauth2/token.rs
+++ b/crates/handlers/src/oauth2/token.rs
@@ -21,7 +21,7 @@ use headers::{CacheControl, Pragma};
 use hyper::StatusCode;
 use mas_config::{OAuth2ClientConfig, OAuth2Config};
 use mas_data_model::{AuthorizationGrantStage, TokenType};
-use mas_iana::jose::JsonWebSignatureAlg;
+use mas_iana::{jose::JsonWebSignatureAlg, oauth::OAuthClientAuthenticationMethod};
 use mas_jose::{
     claims::{AT_HASH, AUD, AUTH_TIME, C_HASH, EXP, IAT, ISS, NONCE, SUB},
     DecodedJsonWebToken, SigningKeystore, StaticKeystore,
@@ -42,8 +42,7 @@ use mas_warp_utils::{
 use oauth2_types::{
     errors::{InvalidGrant, InvalidRequest, OAuth2Error, OAuth2ErrorCode, UnauthorizedClient},
     requests::{
-        AccessTokenRequest, AccessTokenResponse, AuthorizationCodeGrant,
-        ClientAuthenticationMethod, RefreshTokenGrant,
+        AccessTokenRequest, AccessTokenResponse, AuthorizationCodeGrant, RefreshTokenGrant,
     },
     scope::OPENID,
 };
@@ -131,7 +130,7 @@ async fn recover(rejection: Rejection) -> Result<Box<dyn Reply>, Rejection> {
 }
 
 async fn token(
-    _auth: ClientAuthenticationMethod,
+    _auth: OAuthClientAuthenticationMethod,
     client: OAuth2ClientConfig,
     req: AccessTokenRequest,
     key_store: Arc<StaticKeystore>,
diff --git a/crates/iana-codegen/src/main.rs b/crates/iana-codegen/src/main.rs
index abf4f0f5..02fb3d79 100644
--- a/crates/iana-codegen/src/main.rs
+++ b/crates/iana-codegen/src/main.rs
@@ -182,10 +182,12 @@ async fn generate_oauth(client: &Arc<Client>, path: PathBuf) -> anyhow::Result<(
         "https://www.iana.org/assignments/jose/jose.xhtml",
         client.clone(),
     )
-    .load::<TokenTypeHint>()
+    .load::<AccessTokenType>()
     .await?
     .load::<AuthorizationEndpointResponseType>()
     .await?
+    .load::<TokenTypeHint>()
+    .await?
     .load::<TokenEndpointAuthenticationMethod>()
     .await?
     .load::<PkceCodeChallengeMethod>()
diff --git a/crates/iana-codegen/src/oauth.rs b/crates/iana-codegen/src/oauth.rs
index 13a893b7..e21b6768 100644
--- a/crates/iana-codegen/src/oauth.rs
+++ b/crates/iana-codegen/src/oauth.rs
@@ -21,22 +21,25 @@ use crate::{
 
 #[allow(dead_code)]
 #[derive(Debug, Deserialize)]
-pub struct TokenTypeHint {
-    #[serde(rename = "Hint Value")]
+pub struct AccessTokenType {
+    #[serde(rename = "Name")]
     name: String,
+    #[serde(rename = "Additional Token Endpoint Response Parameters")]
+    additional_parameters: String,
+    #[serde(rename = "HTTP Authentication Scheme(s)")]
+    http_schemes: String,
     #[serde(rename = "Change Controller")]
     change_controller: String,
     #[serde(rename = "Reference")]
     reference: String,
 }
 
-impl EnumEntry for TokenTypeHint {
-    const URL: &'static str =
-        "https://www.iana.org/assignments/oauth-parameters/token-type-hint.csv";
-    const SECTIONS: &'static [Section] = &[s("OAuthTokenTypeHint", "OAuth Token Type Hint")];
+impl EnumEntry for AccessTokenType {
+    const URL: &'static str = "https://www.iana.org/assignments/oauth-parameters/token-types.csv";
+    const SECTIONS: &'static [Section] = &[s("OAuthAccessTokenType", "OAuth Access Token Type")];
 
     fn key(&self) -> Option<&'static str> {
-        Some("OAuthTokenTypeHint")
+        Some("OAuthAccessTokenType")
     }
 
     fn name(&self) -> &str {
@@ -82,16 +85,41 @@ pub struct TokenEndpointAuthenticationMethod {
     reference: String,
 }
 
+#[allow(dead_code)]
+#[derive(Debug, Deserialize)]
+pub struct TokenTypeHint {
+    #[serde(rename = "Hint Value")]
+    name: String,
+    #[serde(rename = "Change Controller")]
+    change_controller: String,
+    #[serde(rename = "Reference")]
+    reference: String,
+}
+
+impl EnumEntry for TokenTypeHint {
+    const URL: &'static str =
+        "https://www.iana.org/assignments/oauth-parameters/token-type-hint.csv";
+    const SECTIONS: &'static [Section] = &[s("OAuthTokenTypeHint", "OAuth Token Type Hint")];
+
+    fn key(&self) -> Option<&'static str> {
+        Some("OAuthTokenTypeHint")
+    }
+
+    fn name(&self) -> &str {
+        &self.name
+    }
+}
+
 impl EnumEntry for TokenEndpointAuthenticationMethod {
     const URL: &'static str =
         "https://www.iana.org/assignments/oauth-parameters/token-endpoint-auth-method.csv";
     const SECTIONS: &'static [Section] = &[s(
-        "OAuthTokenEndpointAuthenticationMethod",
+        "OAuthClientAuthenticationMethod",
         "OAuth Token Endpoint Authentication Method",
     )];
 
     fn key(&self) -> Option<&'static str> {
-        Some("OAuthTokenEndpointAuthenticationMethod")
+        Some("OAuthClientAuthenticationMethod")
     }
 
     fn name(&self) -> &str {
diff --git a/crates/iana-codegen/src/traits.rs b/crates/iana-codegen/src/traits.rs
index cc66f152..6fec86e7 100644
--- a/crates/iana-codegen/src/traits.rs
+++ b/crates/iana-codegen/src/traits.rs
@@ -61,7 +61,11 @@ pub trait EnumEntry: DeserializeOwned + Send + Sync {
         None
     }
     fn enum_name(&self) -> String {
-        self.name().replace('+', "_").to_case(Case::Pascal)
+        // Do the case transformation twice to have "N_A" turned to "Na" instead of "NA"
+        self.name()
+            .replace('+', "_")
+            .to_case(Case::Pascal)
+            .to_case(Case::Pascal)
     }
 
     async fn fetch(client: &Client) -> anyhow::Result<Vec<(&'static str, EnumMember)>> {
diff --git a/crates/iana/src/oauth.rs b/crates/iana/src/oauth.rs
index e3e70ada..8b64294e 100644
--- a/crates/iana/src/oauth.rs
+++ b/crates/iana/src/oauth.rs
@@ -21,24 +21,24 @@ use parse_display::{Display, FromStr};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
-/// OAuth Token Type Hint
+/// OAuth Access Token Type
 ///
-/// Source: <https://www.iana.org/assignments/oauth-parameters/token-type-hint.csv>
+/// Source: <https://www.iana.org/assignments/oauth-parameters/token-types.csv>
 #[derive(
     Debug, Clone, Copy, PartialEq, Eq, Hash, Display, FromStr, Serialize, Deserialize, JsonSchema,
 )]
-pub enum OAuthTokenTypeHint {
-    #[serde(rename = "access_token")]
-    #[display("access_token")]
-    AccessToken,
+pub enum OAuthAccessTokenType {
+    #[serde(rename = "Bearer")]
+    #[display("Bearer")]
+    Bearer,
 
-    #[serde(rename = "refresh_token")]
-    #[display("refresh_token")]
-    RefreshToken,
+    #[serde(rename = "N_A")]
+    #[display("N_A")]
+    Na,
 
-    #[serde(rename = "pct")]
-    #[display("pct")]
-    Pct,
+    #[serde(rename = "PoP")]
+    #[display("PoP")]
+    PoP,
 }
 
 /// OAuth Authorization Endpoint Response Type
@@ -81,13 +81,33 @@ pub enum OAuthAuthorizationEndpointResponseType {
     Token,
 }
 
+/// OAuth Token Type Hint
+///
+/// Source: <https://www.iana.org/assignments/oauth-parameters/token-type-hint.csv>
+#[derive(
+    Debug, Clone, Copy, PartialEq, Eq, Hash, Display, FromStr, Serialize, Deserialize, JsonSchema,
+)]
+pub enum OAuthTokenTypeHint {
+    #[serde(rename = "access_token")]
+    #[display("access_token")]
+    AccessToken,
+
+    #[serde(rename = "refresh_token")]
+    #[display("refresh_token")]
+    RefreshToken,
+
+    #[serde(rename = "pct")]
+    #[display("pct")]
+    Pct,
+}
+
 /// OAuth Token Endpoint Authentication Method
 ///
 /// Source: <https://www.iana.org/assignments/oauth-parameters/token-endpoint-auth-method.csv>
 #[derive(
     Debug, Clone, Copy, PartialEq, Eq, Hash, Display, FromStr, Serialize, Deserialize, JsonSchema,
 )]
-pub enum OAuthTokenEndpointAuthenticationMethod {
+pub enum OAuthClientAuthenticationMethod {
     #[serde(rename = "none")]
     #[display("none")]
     None,
diff --git a/crates/oauth2-types/src/lib.rs b/crates/oauth2-types/src/lib.rs
index 09d52b4b..67b84e62 100644
--- a/crates/oauth2-types/src/lib.rs
+++ b/crates/oauth2-types/src/lib.rs
@@ -16,11 +16,46 @@
 #![deny(clippy::all)]
 #![warn(clippy::pedantic)]
 
+use mas_iana::oauth::OAuthAuthorizationEndpointResponseType;
+
+pub trait ResponseTypeExt {
+    fn has_code(&self) -> bool;
+    fn has_token(&self) -> bool;
+    fn has_id_token(&self) -> bool;
+}
+
+impl ResponseTypeExt for OAuthAuthorizationEndpointResponseType {
+    fn has_code(&self) -> bool {
+        matches!(
+            self,
+            Self::Code | Self::CodeToken | Self::CodeIdToken | Self::CodeIdTokenToken
+        )
+    }
+
+    fn has_token(&self) -> bool {
+        matches!(
+            self,
+            Self::Token | Self::CodeToken | Self::IdTokenToken | Self::CodeIdTokenToken
+        )
+    }
+
+    fn has_id_token(&self) -> bool {
+        matches!(
+            self,
+            Self::IdToken | Self::IdTokenToken | Self::CodeIdToken | Self::CodeIdTokenToken
+        )
+    }
+}
+
 pub mod errors;
 pub mod oidc;
 pub mod pkce;
 pub mod requests;
 pub mod scope;
 
+pub mod prelude {
+    pub use crate::{pkce::CodeChallengeMethodExt, ResponseTypeExt};
+}
+
 #[cfg(test)]
 mod test_utils;
diff --git a/crates/oauth2-types/src/oidc.rs b/crates/oauth2-types/src/oidc.rs
index 9baef27c..9a376dd5 100644
--- a/crates/oauth2-types/src/oidc.rs
+++ b/crates/oauth2-types/src/oidc.rs
@@ -14,15 +14,18 @@
 
 use std::collections::HashSet;
 
-use mas_iana::jose::{JsonWebEncryptionAlg, JsonWebEncryptionEnc, JsonWebSignatureAlg};
+use mas_iana::{
+    jose::{JsonWebEncryptionAlg, JsonWebEncryptionEnc, JsonWebSignatureAlg},
+    oauth::{
+        OAuthAuthorizationEndpointResponseType, OAuthClientAuthenticationMethod,
+        PkceCodeChallengeMethod,
+    },
+};
 use serde::Serialize;
 use serde_with::skip_serializing_none;
 use url::Url;
 
-use crate::{
-    pkce::CodeChallengeMethod,
-    requests::{ClientAuthenticationMethod, Display, GrantType, ResponseMode},
-};
+use crate::requests::{Display, GrantType, ResponseMode};
 
 #[derive(Serialize, Clone, Copy, PartialEq, Eq, Hash)]
 #[serde(rename_all = "lowercase")]
@@ -66,7 +69,7 @@ pub struct Metadata {
 
     /// JSON array containing a list of the OAuth 2.0 "response_type" values
     /// that this authorization server supports.
-    pub response_types_supported: Option<HashSet<String>>,
+    pub response_types_supported: Option<HashSet<OAuthAuthorizationEndpointResponseType>>,
 
     /// JSON array containing a list of the OAuth 2.0 "response_mode" values
     /// that this authorization server supports.
@@ -78,7 +81,7 @@ pub struct Metadata {
 
     /// JSON array containing a list of client authentication methods supported
     /// by this token endpoint.
-    pub token_endpoint_auth_methods_supported: Option<HashSet<ClientAuthenticationMethod>>,
+    pub token_endpoint_auth_methods_supported: Option<HashSet<OAuthClientAuthenticationMethod>>,
 
     /// JSON array containing a list of the JWS signing algorithms supported by
     /// the token endpoint for the signature on the JWT used to authenticate the
@@ -109,7 +112,8 @@ pub struct Metadata {
 
     /// JSON array containing a list of client authentication methods supported
     /// by this revocation endpoint.
-    pub revocation_endpoint_auth_methods_supported: Option<HashSet<ClientAuthenticationMethod>>,
+    pub revocation_endpoint_auth_methods_supported:
+        Option<HashSet<OAuthClientAuthenticationMethod>>,
 
     /// JSON array containing a list of the JWS signing algorithms supported by
     /// the revocation endpoint for the signature on the JWT used to
@@ -121,7 +125,8 @@ pub struct Metadata {
 
     /// JSON array containing a list of client authentication methods supported
     /// by this introspection endpoint.
-    pub introspection_endpoint_auth_methods_supported: Option<HashSet<ClientAuthenticationMethod>>,
+    pub introspection_endpoint_auth_methods_supported:
+        Option<HashSet<OAuthClientAuthenticationMethod>>,
 
     /// JSON array containing a list of the JWS signing algorithms supported by
     /// the introspection endpoint for the signature on the JWT used to
@@ -130,7 +135,7 @@ pub struct Metadata {
         Option<HashSet<JsonWebSignatureAlg>>,
 
     /// PKCE code challenge methods supported by this authorization server.
-    pub code_challenge_methods_supported: Option<HashSet<CodeChallengeMethod>>,
+    pub code_challenge_methods_supported: Option<HashSet<PkceCodeChallengeMethod>>,
 
     /// URL of the OP's UserInfo Endpoint.
     pub userinfo_endpoint: Option<Url>,
diff --git a/crates/oauth2-types/src/pkce.rs b/crates/oauth2-types/src/pkce.rs
index 76bbc238..980f4a4f 100644
--- a/crates/oauth2-types/src/pkce.rs
+++ b/crates/oauth2-types/src/pkce.rs
@@ -15,40 +15,23 @@
 use std::borrow::Cow;
 
 use data_encoding::BASE64URL_NOPAD;
-use parse_display::{Display, FromStr};
+use mas_iana::oauth::PkceCodeChallengeMethod;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 
-#[derive(
-    Debug,
-    Hash,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Clone,
-    Copy,
-    Display,
-    FromStr,
-    Serialize,
-    Deserialize,
-)]
-pub enum CodeChallengeMethod {
-    #[serde(rename = "plain")]
-    #[display("plain")]
-    Plain,
+pub trait CodeChallengeMethodExt {
+    #[must_use]
+    fn compute_challenge(self, verifier: &str) -> Cow<'_, str>;
 
-    #[serde(rename = "S256")]
-    #[display("S256")]
-    S256,
+    #[must_use]
+    fn verify(self, challenge: &str, verifier: &str) -> bool;
 }
 
-impl CodeChallengeMethod {
-    #[must_use]
-    pub fn compute_challenge(self, verifier: &str) -> Cow<'_, str> {
+impl CodeChallengeMethodExt for PkceCodeChallengeMethod {
+    fn compute_challenge(self, verifier: &str) -> Cow<'_, str> {
         match self {
-            CodeChallengeMethod::Plain => verifier.into(),
-            CodeChallengeMethod::S256 => {
+            Self::Plain => verifier.into(),
+            Self::S256 => {
                 let mut hasher = Sha256::new();
                 hasher.update(verifier.as_bytes());
                 let hash = hasher.finalize();
@@ -58,15 +41,14 @@ impl CodeChallengeMethod {
         }
     }
 
-    #[must_use]
-    pub fn verify(self, challenge: &str, verifier: &str) -> bool {
+    fn verify(self, challenge: &str, verifier: &str) -> bool {
         self.compute_challenge(verifier) == challenge
     }
 }
 
 #[derive(Serialize, Deserialize)]
 pub struct AuthorizationRequest {
-    pub code_challenge_method: CodeChallengeMethod,
+    pub code_challenge_method: PkceCodeChallengeMethod,
     pub code_challenge: String,
 }
 
diff --git a/crates/oauth2-types/src/requests.rs b/crates/oauth2-types/src/requests.rs
index a81d3c46..71f97a20 100644
--- a/crates/oauth2-types/src/requests.rs
+++ b/crates/oauth2-types/src/requests.rs
@@ -16,6 +16,9 @@ use std::{collections::HashSet, hash::Hash, num::NonZeroU32};
 
 use chrono::{DateTime, Duration, Utc};
 use language_tags::LanguageTag;
+use mas_iana::oauth::{
+    OAuthAccessTokenType, OAuthAuthorizationEndpointResponseType, OAuthTokenTypeHint,
+};
 use parse_display::{Display, FromStr};
 use serde::{Deserialize, Serialize};
 use serde_with::{
@@ -28,29 +31,6 @@ use crate::scope::Scope;
 
 // ref: https://www.iana.org/assignments/oauth-parameters/oauth-parameters.xhtml
 
-#[derive(
-    Debug,
-    Hash,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Clone,
-    Copy,
-    Display,
-    FromStr,
-    Serialize,
-    Deserialize,
-)]
-#[display(style = "snake_case")]
-#[serde(rename_all = "snake_case")]
-pub enum ResponseType {
-    Code,
-    IdToken,
-    Token,
-    None,
-}
-
 #[derive(
     Debug,
     Hash,
@@ -72,37 +52,6 @@ pub enum ResponseMode {
     FormPost,
 }
 
-#[derive(
-    Debug,
-    Hash,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Clone,
-    Copy,
-    Display,
-    FromStr,
-    Serialize,
-    Deserialize,
-)]
-#[serde(rename_all = "snake_case")]
-pub enum ClientAuthenticationMethod {
-    None,
-    ClientSecretPost,
-    ClientSecretBasic,
-    ClientSecretJwt,
-    PrivateKeyJwt,
-}
-
-impl ClientAuthenticationMethod {
-    #[must_use]
-    /// Check if the authentication method is for public client or not
-    pub fn public(&self) -> bool {
-        matches!(self, &Self::None)
-    }
-}
-
 #[derive(
     Debug,
     Hash,
@@ -151,8 +100,7 @@ pub enum Prompt {
 #[serde_as]
 #[derive(Serialize, Deserialize)]
 pub struct AuthorizationRequest {
-    #[serde_as(as = "StringWithSeparator::<SpaceSeparator, ResponseType>")]
-    pub response_type: HashSet<ResponseType>,
+    pub response_type: OAuthAuthorizationEndpointResponseType,
 
     pub client_id: String,
 
@@ -200,25 +148,6 @@ pub struct AuthorizationResponse<R> {
     pub response: R,
 }
 
-#[derive(
-    Debug,
-    Hash,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Clone,
-    Copy,
-    Display,
-    FromStr,
-    Serialize,
-    Deserialize,
-)]
-#[serde(rename_all = "snake_case")]
-pub enum TokenType {
-    Bearer,
-}
-
 #[skip_serializing_none]
 #[derive(Serialize, Deserialize, Debug, PartialEq)]
 pub struct AuthorizationCodeGrant {
@@ -285,7 +214,7 @@ pub struct AccessTokenResponse {
     // TODO: this should be somewhere else
     id_token: Option<String>,
 
-    token_type: TokenType,
+    token_type: OAuthAccessTokenType,
 
     #[serde_as(as = "Option<DurationSeconds<i64>>")]
     expires_in: Option<Duration>,
@@ -300,7 +229,7 @@ impl AccessTokenResponse {
             access_token,
             refresh_token: None,
             id_token: None,
-            token_type: TokenType::Bearer,
+            token_type: OAuthAccessTokenType::Bearer,
             expires_in: None,
             scope: None,
         }
@@ -331,20 +260,13 @@ impl AccessTokenResponse {
     }
 }
 
-#[derive(Serialize, Deserialize, Debug, PartialEq)]
-#[serde(rename_all = "snake_case")]
-pub enum TokenTypeHint {
-    AccessToken,
-    RefreshToken,
-}
-
 #[skip_serializing_none]
 #[derive(Serialize, Deserialize, Debug, PartialEq)]
 pub struct IntrospectionRequest {
     pub token: String,
 
     #[serde(default)]
-    pub token_type_hint: Option<TokenTypeHint>,
+    pub token_type_hint: Option<OAuthTokenTypeHint>,
 }
 
 #[serde_as]
@@ -359,7 +281,7 @@ pub struct IntrospectionResponse {
 
     pub username: Option<String>,
 
-    pub token_type: Option<TokenTypeHint>,
+    pub token_type: Option<OAuthTokenTypeHint>,
 
     #[serde_as(as = "Option<TimestampSeconds>")]
     pub exp: Option<DateTime<Utc>>,
diff --git a/crates/storage/Cargo.toml b/crates/storage/Cargo.toml
index 2840438c..4909af26 100644
--- a/crates/storage/Cargo.toml
+++ b/crates/storage/Cargo.toml
@@ -23,3 +23,4 @@ url = { version = "2.2.2", features = ["serde"] }
 
 oauth2-types = { path = "../oauth2-types" }
 mas-data-model = { path = "../data-model" }
+mas-iana = { path = "../iana" }
diff --git a/crates/storage/src/oauth2/authorization_grant.rs b/crates/storage/src/oauth2/authorization_grant.rs
index e996308e..54dc92a1 100644
--- a/crates/storage/src/oauth2/authorization_grant.rs
+++ b/crates/storage/src/oauth2/authorization_grant.rs
@@ -22,7 +22,8 @@ use mas_data_model::{
     Authentication, AuthorizationCode, AuthorizationGrant, AuthorizationGrantStage, BrowserSession,
     Client, Pkce, Session, User,
 };
-use oauth2_types::{pkce::CodeChallengeMethod, requests::ResponseMode, scope::Scope};
+use mas_iana::oauth::PkceCodeChallengeMethod;
+use oauth2_types::{requests::ResponseMode, scope::Scope};
 use sqlx::PgExecutor;
 use url::Url;
 
@@ -237,12 +238,12 @@ impl TryInto<AuthorizationGrant<PostgresqlBackend>> for GrantLookup {
         let pkce = match (self.grant_code_challenge, self.grant_code_challenge_method) {
             (Some(challenge), Some(challenge_method)) if challenge_method == "plain" => {
                 Some(Pkce {
-                    challenge_method: CodeChallengeMethod::Plain,
+                    challenge_method: PkceCodeChallengeMethod::Plain,
                     challenge,
                 })
             }
             (Some(challenge), Some(challenge_method)) if challenge_method == "S256" => Some(Pkce {
-                challenge_method: CodeChallengeMethod::S256,
+                challenge_method: PkceCodeChallengeMethod::S256,
                 challenge,
             }),
             (None, None) => None,
diff --git a/crates/warp-utils/Cargo.toml b/crates/warp-utils/Cargo.toml
index d5ea353c..cec59cc2 100644
--- a/crates/warp-utils/Cargo.toml
+++ b/crates/warp-utils/Cargo.toml
@@ -35,3 +35,4 @@ mas-templates = { path = "../templates" }
 mas-data-model = { path = "../data-model" }
 mas-storage = { path = "../storage" }
 mas-jose = { path = "../jose" }
+mas-iana = { path = "../iana" }
diff --git a/crates/warp-utils/src/filters/client.rs b/crates/warp-utils/src/filters/client.rs
index d07041af..a73e4eba 100644
--- a/crates/warp-utils/src/filters/client.rs
+++ b/crates/warp-utils/src/filters/client.rs
@@ -18,11 +18,11 @@ use std::collections::HashMap;
 
 use headers::{authorization::Basic, Authorization};
 use mas_config::{OAuth2ClientAuthMethodConfig, OAuth2ClientConfig, OAuth2Config};
+use mas_iana::oauth::OAuthClientAuthenticationMethod;
 use mas_jose::{
     claims::{TimeOptions, AUD, EXP, IAT, ISS, JTI, NBF, SUB},
     DecodedJsonWebToken, JsonWebTokenParts, SharedSecret,
 };
-use oauth2_types::requests::ClientAuthenticationMethod;
 use serde::{de::DeserializeOwned, Deserialize};
 use thiserror::Error;
 use warp::{reject::Reject, Filter, Rejection};
@@ -35,7 +35,7 @@ use crate::errors::WrapError;
 pub fn client_authentication<T: DeserializeOwned + Send + 'static>(
     oauth2_config: &OAuth2Config,
     audience: String,
-) -> impl Filter<Extract = (ClientAuthenticationMethod, OAuth2ClientConfig, T), Error = Rejection>
+) -> impl Filter<Extract = (OAuthClientAuthenticationMethod, OAuth2ClientConfig, T), Error = Rejection>
        + Clone
        + Send
        + Sync
@@ -99,7 +99,7 @@ async fn authenticate_client<T>(
     audience: String,
     credentials: ClientCredentials,
     body: T,
-) -> Result<(ClientAuthenticationMethod, OAuth2ClientConfig, T), Rejection> {
+) -> Result<(OAuthClientAuthenticationMethod, OAuth2ClientConfig, T), Rejection> {
     let (auth_method, client) = match credentials {
         ClientCredentials::Pair {
             client_id,
@@ -114,7 +114,9 @@ async fn authenticate_client<T>(
                 })?;
 
             let auth_method = match (&client.client_auth_method, client_secret, via) {
-                (OAuth2ClientAuthMethodConfig::None, None, _) => ClientAuthenticationMethod::None,
+                (OAuth2ClientAuthMethodConfig::None, None, _) => {
+                    OAuthClientAuthenticationMethod::None
+                }
 
                 (
                     OAuth2ClientAuthMethodConfig::ClientSecretBasic {
@@ -129,7 +131,7 @@ async fn authenticate_client<T>(
                         );
                     }
 
-                    ClientAuthenticationMethod::ClientSecretBasic
+                    OAuthClientAuthenticationMethod::ClientSecretBasic
                 }
 
                 (
@@ -145,7 +147,7 @@ async fn authenticate_client<T>(
                         );
                     }
 
-                    ClientAuthenticationMethod::ClientSecretPost
+                    OAuthClientAuthenticationMethod::ClientSecretPost
                 }
 
                 _ => {
@@ -204,13 +206,13 @@ async fn authenticate_client<T>(
                 OAuth2ClientAuthMethodConfig::PrivateKeyJwt(jwks) => {
                     let store = jwks.key_store();
                     token.verify(&decoded, &store).await.wrap_error()?;
-                    ClientAuthenticationMethod::PrivateKeyJwt
+                    OAuthClientAuthenticationMethod::PrivateKeyJwt
                 }
 
                 OAuth2ClientAuthMethodConfig::ClientSecretJwt { client_secret } => {
                     let store = SharedSecret::new(client_secret);
                     token.verify(&decoded, &store).await.wrap_error()?;
-                    ClientAuthenticationMethod::ClientSecretJwt
+                    OAuthClientAuthenticationMethod::ClientSecretJwt
                 }
 
                 _ => {
@@ -428,7 +430,7 @@ mod tests {
             .await
             .unwrap();
 
-        assert_eq!(auth, ClientAuthenticationMethod::ClientSecretJwt);
+        assert_eq!(auth, OAuthClientAuthenticationMethod::ClientSecretJwt);
         assert_eq!(client.client_id, "secret-jwt");
         assert_eq!(body.foo, "baz");
         assert_eq!(body.bar, "foobar");
@@ -515,7 +517,7 @@ mod tests {
             .await
             .unwrap();
 
-        assert_eq!(auth, ClientAuthenticationMethod::PrivateKeyJwt);
+        assert_eq!(auth, OAuthClientAuthenticationMethod::PrivateKeyJwt);
         assert_eq!(client.client_id, "private-key-jwt");
         assert_eq!(body.foo, "baz");
         assert_eq!(body.bar, "foobar");
@@ -575,7 +577,7 @@ mod tests {
             .await
             .unwrap();
 
-        assert_eq!(auth, ClientAuthenticationMethod::ClientSecretPost);
+        assert_eq!(auth, OAuthClientAuthenticationMethod::ClientSecretPost);
         assert_eq!(client.client_id, "secret-post");
         assert_eq!(body.foo, "baz");
         assert_eq!(body.bar, "foobar");
@@ -607,7 +609,7 @@ mod tests {
             .await
             .unwrap();
 
-        assert_eq!(auth, ClientAuthenticationMethod::ClientSecretBasic);
+        assert_eq!(auth, OAuthClientAuthenticationMethod::ClientSecretBasic);
         assert_eq!(client.client_id, "secret-basic");
         assert_eq!(body.foo, "baz");
         assert_eq!(body.bar, "foobar");
@@ -638,7 +640,7 @@ mod tests {
             .await
             .unwrap();
 
-        assert_eq!(auth, ClientAuthenticationMethod::None);
+        assert_eq!(auth, OAuthClientAuthenticationMethod::None);
         assert_eq!(client.client_id, "public");
         assert_eq!(body.foo, "baz");
         assert_eq!(body.bar, "foobar");