diff --git a/files/ko/_redirects.txt b/files/ko/_redirects.txt
index e211bcd6501754..48d0849814a535 100644
--- a/files/ko/_redirects.txt
+++ b/files/ko/_redirects.txt
@@ -737,8 +737,11 @@
 /ko/docs/Web/JavaScript/Reference/Classes/Class_static_initialization_blocks	/ko/docs/Web/JavaScript/Reference/Classes/Static_initialization_blocks
 /ko/docs/Web/JavaScript/Reference/Classes/Private_class_fields	/ko/docs/Web/JavaScript/Reference/Classes/Private_properties
 /ko/docs/Web/JavaScript/Reference/Errors/Bad_return_or_yield	/ko/docs/Web/JavaScript/Reference/Errors/Bad_return
+/ko/docs/Web/JavaScript/Reference/Errors/Deprecated_octal	/ko/docs/Web/JavaScript/Reference/Errors/Deprecated_octal_literal
 /ko/docs/Web/JavaScript/Reference/Errors/Malformed_formal_parameter	/ko/docs/Web/JavaScript/Reference/Errors/Missing_formal_parameter
+/ko/docs/Web/JavaScript/Reference/Errors/Missing_semicolon_before_statement	/ko/docs/conflicting/Web/JavaScript/Reference/Errors/Unexpected_token
 /ko/docs/Web/JavaScript/Reference/Errors/Not_a_codepoint	/ko/docs/Web/JavaScript/Reference/Errors/Not_a_valid_code_point
+/ko/docs/Web/JavaScript/Reference/Errors/Undefined_prop	/ko/docs/orphaned/Web/JavaScript/Reference/Errors/Undefined_prop
 /ko/docs/Web/JavaScript/Reference/Functions/애로우_펑션	/ko/docs/Web/JavaScript/Reference/Functions/Arrow_functions
 /ko/docs/Web/JavaScript/Reference/Global_Functions	/ko/docs/Web/JavaScript/Reference/Global_Objects
 /ko/docs/Web/JavaScript/Reference/Global_Objects/Array/constructor	/ko/docs/Web/JavaScript/Reference/Global_Objects/Array
diff --git a/files/ko/_wikihistory.json b/files/ko/_wikihistory.json
index 8e31ac50bb4bbc..ce92bdf2971218 100644
--- a/files/ko/_wikihistory.json
+++ b/files/ko/_wikihistory.json
@@ -7903,7 +7903,7 @@
     "modified": "2020-03-12T19:44:32.792Z",
     "contributors": ["magnoliaa"]
   },
-  "Web/JavaScript/Reference/Errors/Deprecated_octal": {
+  "Web/JavaScript/Reference/Errors/Deprecated_octal_literal": {
     "modified": "2020-03-12T19:48:30.330Z",
     "contributors": ["magnoliaa"]
   },
@@ -7971,10 +7971,6 @@
     "modified": "2020-03-12T19:47:45.484Z",
     "contributors": ["Olivia_J"]
   },
-  "Web/JavaScript/Reference/Errors/Missing_semicolon_before_statement": {
-    "modified": "2020-03-12T19:46:46.133Z",
-    "contributors": ["magnoliaa"]
-  },
   "Web/JavaScript/Reference/Errors/More_arguments_needed": {
     "modified": "2020-03-12T19:48:33.843Z",
     "contributors": ["magnoliaa"]
@@ -8035,10 +8031,6 @@
     "modified": "2020-03-12T19:44:33.741Z",
     "contributors": ["magnoliaa"]
   },
-  "Web/JavaScript/Reference/Errors/Undefined_prop": {
-    "modified": "2020-03-12T19:44:33.728Z",
-    "contributors": ["magnoliaa"]
-  },
   "Web/JavaScript/Reference/Errors/Unexpected_token": {
     "modified": "2020-03-12T19:44:11.696Z",
     "contributors": ["ChangSungsil"]
@@ -10803,6 +10795,10 @@
     "modified": "2020-03-12T19:44:24.834Z",
     "contributors": ["magnoliaa"]
   },
+  "conflicting/Web/JavaScript/Reference/Errors/Unexpected_token": {
+    "modified": "2020-03-12T19:46:46.133Z",
+    "contributors": ["magnoliaa"]
+  },
   "orphaned/Learn/Front-end_web_developer": {
     "modified": "2020-09-26T16:42:10.726Z",
     "contributors": ["DeadIntegral"]
@@ -10823,6 +10819,10 @@
     "modified": "2019-03-23T22:50:49.180Z",
     "contributors": ["Basix"]
   },
+  "orphaned/Web/JavaScript/Reference/Errors/Undefined_prop": {
+    "modified": "2020-03-12T19:44:33.728Z",
+    "contributors": ["magnoliaa"]
+  },
   "orphaned/Web/SVG/Element/altGlyph": {
     "modified": "2020-10-15T21:40:13.413Z",
     "contributors": ["alattalatta", "Sebastianz", "dewey94esb"]
diff --git a/files/ko/web/javascript/reference/errors/missing_semicolon_before_statement/index.md b/files/ko/conflicting/web/javascript/reference/errors/unexpected_token/index.md
similarity index 94%
rename from files/ko/web/javascript/reference/errors/missing_semicolon_before_statement/index.md
rename to files/ko/conflicting/web/javascript/reference/errors/unexpected_token/index.md
index 9efaba996322d1..5fa6311357e7ec 100644
--- a/files/ko/web/javascript/reference/errors/missing_semicolon_before_statement/index.md
+++ b/files/ko/conflicting/web/javascript/reference/errors/unexpected_token/index.md
@@ -1,6 +1,7 @@
 ---
 title: "SyntaxError: missing ; before statement"
-slug: Web/JavaScript/Reference/Errors/Missing_semicolon_before_statement
+slug: conflicting/Web/JavaScript/Reference/Errors/Unexpected_token
+original_slug: Web/JavaScript/Reference/Errors/Missing_semicolon_before_statement
 ---
 
 {{jsSidebar("Errors")}}
diff --git a/files/ko/web/javascript/reference/errors/undefined_prop/index.md b/files/ko/orphaned/web/javascript/reference/errors/undefined_prop/index.md
similarity index 90%
rename from files/ko/web/javascript/reference/errors/undefined_prop/index.md
rename to files/ko/orphaned/web/javascript/reference/errors/undefined_prop/index.md
index 8ef49e7a2bc610..2e01ba6b21c043 100644
--- a/files/ko/web/javascript/reference/errors/undefined_prop/index.md
+++ b/files/ko/orphaned/web/javascript/reference/errors/undefined_prop/index.md
@@ -1,6 +1,7 @@
 ---
-title: 'ReferenceError: reference to undefined property "x"'
-slug: Web/JavaScript/Reference/Errors/Undefined_prop
+title: "ReferenceError: reference to undefined property \"x\""
+slug: orphaned/Web/JavaScript/Reference/Errors/Undefined_prop
+original_slug: Web/JavaScript/Reference/Errors/Undefined_prop
 ---
 
 {{jsSidebar("Errors")}}
diff --git a/files/ko/web/javascript/reference/errors/deprecated_octal/index.md b/files/ko/web/javascript/reference/errors/deprecated_octal_literal/index.md
similarity index 89%
rename from files/ko/web/javascript/reference/errors/deprecated_octal/index.md
rename to files/ko/web/javascript/reference/errors/deprecated_octal_literal/index.md
index cd593ceb7be349..c138da6fa7a2ea 100644
--- a/files/ko/web/javascript/reference/errors/deprecated_octal/index.md
+++ b/files/ko/web/javascript/reference/errors/deprecated_octal_literal/index.md
@@ -1,6 +1,7 @@
 ---
-title: 'SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated'
-slug: Web/JavaScript/Reference/Errors/Deprecated_octal
+title: "SyntaxError: \"0\"-prefixed octal literals and octal escape seq. are deprecated"
+slug: Web/JavaScript/Reference/Errors/Deprecated_octal_literal
+original_slug: Web/JavaScript/Reference/Errors/Deprecated_octal
 ---
 
 {{jsSidebar("Errors")}}