update MD by dispatch event pingcap/docs master

Author: github-actions

markdown-pages/en/tidb/master/keywords.md

@@ -8,7 +8,7 @@ aliases: ['/docs/dev/keywords-and-reserved-words/','/docs/dev/reference/sql/lang
 
 This article introduces the keywords in TiDB, the differences between reserved words and non-reserved words and summarizes all keywords for the query.
 
-Keywords are words that have special meanings in SQL statements, such as [`SELECT`](/sql-statements/sql-statement-select.md), [`UPDATE`](/sql-statements/sql-statement-update.md), and [`DELETE`](/sql-statements/sql-statement-delete.md). Some of them can be used as identifiers directly, which are called **non-reserved keywords**. Some of them require special treatment before being used as identifiers, which are called **reserved keywords**. However, there are special non-reserved keywords that might still require special treatment. It is recommended that you treat them as reserved keywords.
+Keywords are words that have special meanings in SQL statements, such as [`SELECT`](/sql-statements/sql-statement-select.md), [`UPDATE`](/sql-statements/sql-statement-update.md), and [`DELETE`](/sql-statements/sql-statement-delete.md). Some of them can be used as identifiers directly, which are called **non-reserved keywords**. Some of them require special treatment before being used as identifiers, which are called **reserved keywords**. 
 
 To use the reserved keywords as identifiers, you must enclose them in backticks `` ` ``:
 
@@ -54,7 +54,7 @@ You can use the [`tidb_enable_window_function`](/system-variables.md#tidb_enable
 
 ## Keyword list
 
-The following list shows the keywords in TiDB. Reserved keywords are marked with `(R)`. Reserved keywords for [Window Functions](/functions-and-operators/window-functions.md) are marked with `(R-Window)`. Special non-reserved keywords that need to be escaped with backticks `` ` `` are marked with `(S)`.
+The following list shows the keywords in TiDB. Reserved keywords are marked with `(R)`. Reserved keywords for [Window Functions](/functions-and-operators/window-functions.md) are marked with `(R-Window)`.
 
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