diff --git a/src/class-elements/delete-error/cls-decl-field-delete.template b/src/class-elements/delete-error/cls-decl-field-delete.template
index 1d6a0188eb45f3cd1fe4a104409ca3eff77d5134..70976fd66b2a8451253cc473211797ddc7a52c01 100644
--- a/src/class-elements/delete-error/cls-decl-field-delete.template
+++ b/src/class-elements/delete-error/cls-decl-field-delete.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/statements/class/syntax/early-errors/delete/field-delete-
 name: in field
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-decl-method-delete-covered.template b/src/class-elements/delete-error/cls-decl-method-delete-covered.template
index cb9d3845ad2bf58340696d9a239fb6e75f31b5bf..afd81451afd708308e2cbf2b69af2d9607faae42 100644
--- a/src/class-elements/delete-error/cls-decl-method-delete-covered.template
+++ b/src/class-elements/delete-error/cls-decl-method-delete-covered.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/statements/class/syntax/early-errors/delete/method-delete-covered-
 name: in method, covered
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-decl-method-delete-twice-covered.template b/src/class-elements/delete-error/cls-decl-method-delete-twice-covered.template
index cdce44e0742f92116818f7e0feb53c6275d0b5b1..ac490c68586f36f2ded69d27d75756429022cc2b 100644
--- a/src/class-elements/delete-error/cls-decl-method-delete-twice-covered.template
+++ b/src/class-elements/delete-error/cls-decl-method-delete-twice-covered.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/statements/class/syntax/early-errors/delete/method-delete-twice-covered-
 name: in method, recursively covered
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-decl-method-delete.template b/src/class-elements/delete-error/cls-decl-method-delete.template
index 38ed396afa7620154043ef835046746e21803557..d23ceea052523c84dc72ff220d774155bf0e5cb1 100644
--- a/src/class-elements/delete-error/cls-decl-method-delete.template
+++ b/src/class-elements/delete-error/cls-decl-method-delete.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/statements/class/syntax/early-errors/delete/method-delete-
 name: in method
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-expr-field-delete-covered.template b/src/class-elements/delete-error/cls-expr-field-delete-covered.template
index b0b51d7204fefb6f83088ff5c967275957977574..824c0d042fded7868a5d69f48d0ea3844c6cf867 100644
--- a/src/class-elements/delete-error/cls-expr-field-delete-covered.template
+++ b/src/class-elements/delete-error/cls-expr-field-delete-covered.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/expressions/class/syntax/early-errors/delete/field-delete-covered-
 name: in field, covered
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-expr-field-delete-twice-covered.template b/src/class-elements/delete-error/cls-expr-field-delete-twice-covered.template
index 139edf01520ec831e9c92103f9fda3ba60769dd7..a48ab245372a3b6dd358ba189f15606fc14cdcc7 100644
--- a/src/class-elements/delete-error/cls-expr-field-delete-twice-covered.template
+++ b/src/class-elements/delete-error/cls-expr-field-delete-twice-covered.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/expressions/class/syntax/early-errors/delete/field-delete-twice-covered-
 name: in field, recursively covered
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-expr-field-delete.template b/src/class-elements/delete-error/cls-expr-field-delete.template
index ff5a8f79818664aed076a98bfed3aff2e5c2276d..0107722ec48fdeccaf5fb29c74adcf07e15d7d47 100644
--- a/src/class-elements/delete-error/cls-expr-field-delete.template
+++ b/src/class-elements/delete-error/cls-expr-field-delete.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/expressions/class/syntax/early-errors/delete/field-delete-
 name: in field
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-expr-method-delete-covered.template b/src/class-elements/delete-error/cls-expr-method-delete-covered.template
index b7682d9b8743a20ad44149971fbc4dbb832c1b10..71314dc6ba9661ff17a08a6835c4db1cfac0b360 100644
--- a/src/class-elements/delete-error/cls-expr-method-delete-covered.template
+++ b/src/class-elements/delete-error/cls-expr-method-delete-covered.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/expressions/class/syntax/early-errors/delete/method-delete-covered-
 name: in method, covered
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-expr-method-delete-twice-covered.template b/src/class-elements/delete-error/cls-expr-method-delete-twice-covered.template
index b6a84940ee1311bc842f3ff8dc8a35b96ee35551..ff69927b5214d945c5908ba66a97ca42b9527745 100644
--- a/src/class-elements/delete-error/cls-expr-method-delete-twice-covered.template
+++ b/src/class-elements/delete-error/cls-expr-method-delete-twice-covered.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/expressions/class/syntax/early-errors/delete/method-delete-twice-covered-
 name: in method, recursively covered
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression
diff --git a/src/class-elements/delete-error/cls-expr-method-delete.template b/src/class-elements/delete-error/cls-expr-method-delete.template
index 476b7d67291f2e6791bbd292c499f0584f9938b5..7fb9c7fc2b319b466ca86c15699936502a28d926 100644
--- a/src/class-elements/delete-error/cls-expr-method-delete.template
+++ b/src/class-elements/delete-error/cls-expr-method-delete.template
@@ -6,6 +6,9 @@ esid: sec-class-definitions-static-semantics-early-errors
 path: language/expressions/class/syntax/early-errors/delete/method-delete-
 name: in method
 info: |
+  This file must never use the onlyStrict flag as the strict mode should always
+  be observed inside class bodies.
+
   Static Semantics: Early Errors
 
     UnaryExpression : delete UnaryExpression