diff --git a/scripts/tests/patterns.test.ts b/scripts/tests/patterns.test.ts
index f85ef3d..e26aba3 100644
--- a/scripts/tests/patterns.test.ts
+++ b/scripts/tests/patterns.test.ts
@@ -33,6 +33,7 @@ describe('broad difference-pattern choices', () => {
     expect(patternChoicesMatch('0001', DEFAULT_PATTERN_CHOICES)).toBe(true)
     expect(patternChoicesMatch('0112', DEFAULT_PATTERN_CHOICES)).toBe(true)
     expect(patternChoicesMatch('0123', DEFAULT_PATTERN_CHOICES)).toBe(true)
+    expect(patternChoicesMatch('01234', DEFAULT_PATTERN_CHOICES)).toBe(true)
   })
 
   it('lets an exact pattern replace its broad group', () => {
@@ -40,6 +41,7 @@ describe('broad difference-pattern choices', () => {
       '0001',
       'v3',
       'v4',
+      'v5',
     ])
   })
 
@@ -66,6 +68,16 @@ describe('pattern choices and hidden columns', () => {
 })
 
 describe('pattern choice URL encoding', () => {
+  it('includes five-form rows in the serialized default', () => {
+    expect(serializePatternChoices(DEFAULT_PATTERN_CHOICES)).toBe('v2,v3,v4,v5')
+  })
+
+  it('keeps an explicit five-form opt-out in the URL', () => {
+    const value = ['v2', 'v3', 'v4']
+    expect(serializePatternChoices(value)).toBe('v2,v3,v4')
+    expect(parsePatternChoices(serializePatternChoices(value))).toEqual(value)
+  })
+
   it('round-trips broad and exact choices', () => {
     const value = ['v3', '0001', 'v2']
     expect(parsePatternChoices(serializePatternChoices(value))).toEqual([
diff --git a/shared/patterns.ts b/shared/patterns.ts
index c4a6c9b..4918a00 100644
--- a/shared/patterns.ts
+++ b/shared/patterns.ts
@@ -7,7 +7,12 @@ import { varietyOf } from './row.ts'
  */
 const VARIETY_CHOICE = /^v([1-9]\d*)$/
 
-export const DEFAULT_PATTERN_CHOICES = ['v2', 'v3', 'v4'] as const
+/**
+ * Every non-identical variety is on by default, including the fifth form that
+ * becomes applicable when the opt-in Korean column is shown. Choices that need
+ * more columns than are currently visible stay serialized but do not filter.
+ */
+export const DEFAULT_PATTERN_CHOICES = ['v2', 'v3', 'v4', 'v5'] as const
 export const ALL_PATTERN_CHOICES = 'all'
 
 export const varietyChoice = (variety: number): string => `v${variety}`