diff --git a/unified-data-policy.md b/unified-data-policy.md
index 935d5247151055e27efc7ab2802fa91aba52197b..401b212fa0039d1f8903b20e7be57fb7982abb63 100644
--- a/unified-data-policy.md
+++ b/unified-data-policy.md
@@ -14,13 +14,13 @@
 
 > `sensitive` means I don't want to leak it, `important` means I don't want to lost it. 
 
-- type D: non-sensitive important data, such as environent setup script, software installation packs, saved movies, ...
+- type I2: non-sensitive important data, such as environent setup script, software installation packs, saved movies, ...
 
 - type I: public personal data, or non-important public data. 
 
-- type N2: sensitive important personal data, such as photos, development, game save...
+- type C2: sensitive important personal data, such as photos, development, game save...
 
-- type N1: sensitive non-important personal data, such as system logs, chat logs, screenshots, web history, development environment, ...
+- type C: sensitive non-important personal data, such as system logs, chat logs, screenshots, web history, development environment, ...
 
 - type M: secret keys/seeds/passwords, server userdata... 
 
@@ -34,14 +34,14 @@
 |---|---|---|---|---|
 |M|Always, by GPG master key or super key|First-party|Level 4|extraDisk/.backup/typeM|
 |MX|Always, by cold key and super key|First-party|Level 4|extraDisk/.backup/typeM/gpg-masterkey.tar.gz.gpg|
-|N2|Only if accessed by untrusted device|First-party or Third-party|Level 3|~/extraDisk/.backup, online services|
-|N1|Always, by device encryption|First-party or Third-party|Level 1|normal encrypted devices|
-|D|Optional|First-party or Third-party|Level 2|nfs/rpc\_downloads|
+|C2|Only if accessed by untrusted device|First-party or Third-party|Level 3|~/extraDisk/.backup, online services|
+|C|Always, by device encryption|First-party or Third-party|Level 1|normal encrypted devices|
+|I2|Optional|First-party or Third-party|Level 2|nfs/rpc\_downloads|
 |I|Optional|First-party or Third-party|Level 1|normal devices|
 
 |Properties|Important|Non-Important|
 |---|---|---|
-|Sensitive|MX,M,N2|N1|
-|Non-sensitive|D|I|
+|Sensitive|MX,M,C2|C|
+|Non-sensitive|I2|I|
 
 All device storing / processing unencrypted sensitive data, must either using Fully-Open-Source-Software, or be disconnected from Internet and destroyed afterward.