diff --git a/crates/handlers/src/graphql/mutations/user.rs b/crates/handlers/src/graphql/mutations/user.rs
index b5a0902e9..ec9d2afe0 100644
--- a/crates/handlers/src/graphql/mutations/user.rs
+++ b/crates/handlers/src/graphql/mutations/user.rs
@@ -388,6 +388,13 @@ impl ResendRecoveryEmailPayload {
 #[derive(InputObject)]
 pub struct DeactivateUserInput {
     /// Whether to ask the homeserver to GDPR-erase the user
+    ///
+    /// This is equivalent to the `erase` parameter on the
+    /// `/_matrix/client/v3/account/deactivate` C-S API, which is
+    /// implementation-specific.
+    ///
+    /// What Synapse does is documented here:
+    /// <https://element-hq.github.io/synapse/latest/admin_api/user_admin_api.html#deactivate-account>
     hs_erase: bool,
 
     /// The password of the user to deactivate.
diff --git a/frontend/schema.graphql b/frontend/schema.graphql
index 05a330d14..9cf0ca600 100644
--- a/frontend/schema.graphql
+++ b/frontend/schema.graphql
@@ -607,6 +607,13 @@ The input for the `deactivateUser` mutation.
 input DeactivateUserInput {
   """
   Whether to ask the homeserver to GDPR-erase the user
+
+  This is equivalent to the `erase` parameter on the
+  `/_matrix/client/v3/account/deactivate` C-S API, which is
+  implementation-specific.
+
+  What Synapse does is documented here:
+  <https://element-hq.github.io/synapse/latest/admin_api/user_admin_api.html#deactivate-account>
   """
   hsErase: Boolean!
   """
diff --git a/frontend/src/gql/graphql.ts b/frontend/src/gql/graphql.ts
index 46df85274..38795b6cb 100644
--- a/frontend/src/gql/graphql.ts
+++ b/frontend/src/gql/graphql.ts
@@ -391,7 +391,16 @@ export type DateFilter = {
 
 /** The input for the `deactivateUser` mutation. */
 export type DeactivateUserInput = {
-  /** Whether to ask the homeserver to GDPR-erase the user */
+  /**
+   * Whether to ask the homeserver to GDPR-erase the user
+   *
+   * This is equivalent to the `erase` parameter on the
+   * `/_matrix/client/v3/account/deactivate` C-S API, which is
+   * implementation-specific.
+   *
+   * What Synapse does is documented here:
+   * <https://element-hq.github.io/synapse/latest/admin_api/user_admin_api.html#deactivate-account>
+   */
   hsErase: Scalars['Boolean']['input'];
   /** The password of the user to deactivate. */
   password?: InputMaybe<Scalars['String']['input']>;