diff --git a/README.md b/README.md
index 140e031..fa4a0d5 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ For the deploy tutorial of AUA, please refer to [How to deploy AUA](/deploy.md).
 
 ### Note
 
-> Some APIs have an access limit of 10 requests per IP per day without a token.
+> Some APIs will be inaccessible without a token.
 
 ### Community
 
@@ -35,16 +35,14 @@ For the deploy tutorial of AUA, please refer to [How to deploy AUA](/deploy.md).
 
 + [data/update](/data/update.md)
 + [data/theory](/data/theory.md)
-+ [data/playdata](/data/playdata.md)
-+ [data/density](/data/density.md)
 + [data/challenge](/data/challenge.md) [^2]
 + [data/cert](/data/cert.md) [^3]
 
-[^1]: The `assets/preview` API is not available for release version of AUA. It is provided by [AffPreview](https://github.com/Arcaea-Infinity/Aff2Preview).
+[^1]: The `assets/preview` API is not available for release version. It is provided by [AffPreview](https://github.com/Arcaea-Infinity/Aff2Preview).
 
-[^2]: The `data/challenge` API is not available for release version of AUA.
+[^2]: The `data/challenge` API is not available for release version.
 
-[^3]: The `data/cert` API is not available for release version of AUA.
+[^3]: The `data/cert` API is not available for release version.
 
 ### Error status
 
diff --git a/assets/preview.md b/assets/preview.md
index c34e548..7614c7d 100644
--- a/assets/preview.md
+++ b/assets/preview.md
@@ -12,6 +12,8 @@
 
 * Enable Cors
 
+* Need Token
+
 #### Example
 
 + `{apiurl}/botarcapi/assets/preview?songid=ifi`
diff --git a/data/density.md b/data/density.md
deleted file mode 100644
index abb7cf3..0000000
--- a/data/density.md
+++ /dev/null
@@ -1,42 +0,0 @@
-## data/density
-
-> Note: It is a large data set, so it is not recommended to use this API frequently.
-
-| arguments  | description                          | optional                                                |
-|:-----------|:-------------------------------------|---------------------------------------------------------|
-| songname   | any song name for fuzzy querying     | true when songid or file is not null, otherwise false   |
-| songid     | sid in Arcaea songlist               | true when songname or file is not null, otherwise false |
-| difficulty | accept format are 3 or byn or beyond | true                                                    |
-
-###### Tag
-
-* Enable Cors
-
-#### Example
-
-+ `{apiurl}/botarcapi/data/density?songid=ifi&difficulty=2`
-
-##### Return data (Edited for readability)
-
-```json5
-{
-  "status": 0,
-  "content": [
-    [
-      1000, // fscore, (score/10000)
-      115, // fpotential (potential/10)
-      1 // count
-    ],
-    [
-      1000,
-      116,
-      1
-    ],
-    [
-      1000,
-      117,
-      1
-    ]
-  ]
-}
-```
diff --git a/data/playdata.md b/data/playdata.md
deleted file mode 100644
index 59b5022..0000000
--- a/data/playdata.md
+++ /dev/null
@@ -1,59 +0,0 @@
-## data/playdata
-
-> Note: It is a large data set, so it is not recommended to use this API frequently.
-
-> Note: It is recommended to use `data/density` API.
-
-| arguments  | description                          | optional                                                |
-|:-----------|:-------------------------------------|---------------------------------------------------------|
-| songname   | any song name for fuzzy querying     | true when songid or file is not null, otherwise false   |
-| songid     | sid in Arcaea songlist               | true when songname or file is not null, otherwise false |
-| difficulty | accept format are 3 or byn or beyond | true                                                    |
-| start      | range of potential start (100*)      | false                                                   |
-| end        | range of potential end  (100*)       | false                                                   |
-
-###### Tag
-
-* Enable Cors
-
-#### Example
-
-+ `{apiurl}/botarcapi/data/playdata?songid=ifi&difficulty=2&start=1280&end=1288`
-
-##### Return data (Edited for readability)
-
-```json5
-{
-  "status": 0,
-  "content": [
-    {
-      "fscore": 1000, // (score/10000)
-      "count": 125
-    },
-    {
-      "fscore": 999,
-      "count": 28
-    },
-    {
-      "fscore": 998,
-      "count": 26
-    },
-    {
-      "fscore": 997,
-      "count": 19
-    },
-    {
-      "fscore": 996,
-      "count": 14
-    },
-    {
-      "fscore": 995,
-      "count": 6
-    },
-    {
-      "fscore": 994,
-      "count": 2
-    }
-  ]
-}
-```