diff --git a/Software/Applications/DD/DD_命令的使用.md b/Software/Applications/DD/DD_命令的使用.md
index c3329b3..4d17ac7 100644
--- a/Software/Applications/DD/DD_命令的使用.md
+++ b/Software/Applications/DD/DD_命令的使用.md
@@ -19,14 +19,19 @@ dd iflag=direct,nonblock if=\<in file name\> oflag=direct,nonblock of=/dev/\<out
 
 多个 Flag 之间可以用逗号分割，含义如下表。
 
-| flags     | Description                                  |
-|-----------|----------------------------------------------|
-| direct    | 读写数据采用直接 IO 方式                        |
-| directory | 读写失败除非是 directory                       |
-| dsync     | 读写数据采用同步 IO                            |
-| sync      | 同上，但是针对元数据                            |
-| fullblock | accumulate full blocks of input              |
-| nonblock  | 读写数据采用非阻塞 IO 方式                      |
-| noatime   | 读写数据不更新访问时间                          |
-| noctty    | do not assign controlling terminal from file |
-| nofollow  | do not follow symlinks                       |
+| Flag        | Description                                                       |
+|-------------|-------------------------------------------------------------------|
+| append      | append mode (makes sense only for output; conv=notrunc suggested) |
+| direct      | use direct I/O for data                                           |
+| directory   | fail unless a directory                                           |
+| dsync       | use synchronized I/O for data                                     |
+| sync        | likewise, but also for metadata                                   |
+| fullblock   | accumulate full blocks of input (iflag only)                      |
+| nonblock    | use non-blocking I/O                                              |
+| noatime     | do not update access time                                         |
+| nocache     | Request to drop cache.  See also oflag=sync                       |
+| noctty      | do not assign controlling terminal from file                      |
+| nofollow    | do not follow symlinks                                            |
+| count_bytes | treat 'count=N' as a byte count (iflag only)                      |
+| skip_bytes  | treat 'skip=N' as a byte count (iflag only)                       |
+| seek_bytes  | treat 'seek=N' as a byte count (oflag only)                       |