2 files changed, 30 insertions, 5 deletions
diff --git a/docs/admin_api/rooms.md b/docs/admin_api/rooms.md
index 15b83e9824..0f267d2b7b 100644
--- a/docs/admin_api/rooms.md
+++ b/docs/admin_api/rooms.md
@@ -369,7 +369,9 @@ to the new room will have power level `-10` by default, and thus be unable to sp
 If `block` is `True` it prevents new joins to the old room.
 
 This API will remove all trace of the old room from your database after removing
-all local users.
+all local users. If `purge` is `true` (the default), all traces of the old room will
+be removed from your database after removing all local users. If you do not want
+this to happen, set `purge` to `false`.
 Depending on the amount of history being purged a call to the API may take
 several minutes or longer.
 
@@ -388,7 +390,8 @@ with a body of:
     "new_room_user_id": "@someuser:example.com",
     "room_name": "Content Violation Notification",
     "message": "Bad Room has been shutdown due to content violations on this server. Please review our Terms of Service.",
-    "block": true
+    "block": true,
+    "purge": true
 }
 ```
 
@@ -430,8 +433,10 @@ The following JSON body parameters are available:
               `new_room_user_id` in the new room. Ideally this will clearly convey why the
                original room was shut down. Defaults to `Sharing illegal content on this server
                is not permitted and rooms in violation will be blocked.`
-* `block` - Optional. If set to `true`, this room will be added to a blocking list, preventing future attempts to
-  join the room. Defaults to `false`.
+* `block` - Optional. If set to `true`, this room will be added to a blocking list, preventing
+            future attempts to join the room. Defaults to `false`.
+* `purge` - Optional. If set to `true`, it will remove all traces of the room from your database.
+            Defaults to `true`.
 
 The JSON body must not be empty. The body must be at least `{}`.
 
diff --git a/docs/admin_api/shutdown_room.md b/docs/admin_api/shutdown_room.md
index 808caeec79..2ff552bcb3 100644
--- a/docs/admin_api/shutdown_room.md
+++ b/docs/admin_api/shutdown_room.md
@@ -33,7 +33,7 @@ You will need to authenticate with an access token for an admin user.
 * `message` - Optional. A string containing the first message that will be sent as
               `new_room_user_id` in the new room. Ideally this will clearly convey why the
                original room was shut down.
-              
+
 If not specified, the default value of `room_name` is "Content Violation
 Notification". The default value of `message` is "Sharing illegal content on
 othis server is not permitted and rooms in violation will be blocked."
@@ -72,3 +72,23 @@ Response:
     "new_room_id": "!newroomid:example.com",
 },
 ```
+
+## Undoing room shutdowns
+
+*Note*: This guide may be outdated by the time you read it. By nature of room shutdowns being performed at the database level,
+the structure can and does change without notice.
+
+First, it's important to understand that a room shutdown is very destructive. Undoing a shutdown is not as simple as pretending it
+never happened - work has to be done to move forward instead of resetting the past.
+
+1. For safety reasons, it is recommended to shut down Synapse prior to continuing.
+2. In the database, run `DELETE FROM blocked_rooms WHERE room_id = '!example:example.org';`
+   * For caution: it's recommended to run this in a transaction: `BEGIN; DELETE ...;`, verify you got 1 result, then `COMMIT;`.
+   * The room ID is the same one supplied to the shutdown room API, not the Content Violation room.
+3. Restart Synapse (required).
+
+You will have to manually handle, if you so choose, the following:
+
+* Aliases that would have been redirected to the Content Violation room.
+* Users that would have been booted from the room (and will have been force-joined to the Content Violation room).
+* Removal of the Content Violation room if desired.