diff --git a/projects/cdk/types/index.ts b/projects/cdk/types/index.ts
index 691b4f57d788f..ec6a121414f3e 100644
--- a/projects/cdk/types/index.ts
+++ b/projects/cdk/types/index.ts
@@ -4,4 +4,5 @@ export * from './mapper';
 export * from './matcher';
 export * from './rounding';
 export * from './safe-html';
+export * from './suggestive-string';
 export * from './values-of';
diff --git a/projects/cdk/types/suggestive-string.ts b/projects/cdk/types/suggestive-string.ts
new file mode 100644
index 0000000000000..9d9b407569882
--- /dev/null
+++ b/projects/cdk/types/suggestive-string.ts
@@ -0,0 +1,11 @@
+export type TuiLooseUnion<U> =
+    | U
+    | (U extends string
+          ? Record<never, never> & string
+          : U extends number
+            ? Record<never, never> & number
+            : U extends symbol
+              ? Record<never, never> & symbol
+              : U extends bigint
+                ? Record<never, never> & bigint
+                : never);
diff --git a/projects/core/directives/appearance/appearance.options.ts b/projects/core/directives/appearance/appearance.options.ts
index 23170b25c27f0..5705cf03b17dc 100644
--- a/projects/core/directives/appearance/appearance.options.ts
+++ b/projects/core/directives/appearance/appearance.options.ts
@@ -1,10 +1,11 @@
 import type {ExistingProvider, ProviderToken} from '@angular/core';
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
 import {tuiCreateToken, tuiProvide} from '@taiga-ui/cdk/utils/miscellaneous';
 
 /**
  * Bundled appearances for autocomplete purposes, not exported on purpose
  */
-type Appearance =
+type Appearance = TuiLooseUnion<
     | 'accent'
     | 'destructive'
     | 'error'
@@ -22,7 +23,7 @@ type Appearance =
     | 'textfield'
     | 'warning'
     | 'whiteblock'
-    | (Record<never, never> & string);
+>;
 
 export interface TuiAppearanceOptions {
     readonly appearance: Appearance;
diff --git a/projects/core/pipes/flag/flag.pipe.ts b/projects/core/pipes/flag/flag.pipe.ts
index 57dd8d0524b3a..f1ab82738279a 100644
--- a/projects/core/pipes/flag/flag.pipe.ts
+++ b/projects/core/pipes/flag/flag.pipe.ts
@@ -1,8 +1,11 @@
 import type {PipeTransform} from '@angular/core';
 import {inject, Pipe} from '@angular/core';
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
 import {TUI_ASSETS_PATH} from '@taiga-ui/core/tokens';
 import type {TuiCountryIsoCode} from '@taiga-ui/i18n/types';
 
+type IsoCode = TuiLooseUnion<TuiCountryIsoCode>;
+
 @Pipe({
     standalone: true,
     name: 'tuiFlag',
@@ -10,18 +13,10 @@ import type {TuiCountryIsoCode} from '@taiga-ui/i18n/types';
 export class TuiFlagPipe implements PipeTransform {
     private readonly staticPath = inject(TUI_ASSETS_PATH);
 
-    public transform(
-        countryIsoCode: TuiCountryIsoCode | (Record<never, never> & string),
-    ): string;
-    public transform(
-        countryIsoCode: TuiCountryIsoCode | (Record<never, never> & string) | undefined,
-    ): string | null;
-    public transform(
-        countryIsoCode?: TuiCountryIsoCode | (Record<never, never> & string) | null,
-    ): string | null;
-    public transform(
-        countryIsoCode?: TuiCountryIsoCode | (Record<never, never> & string) | null,
-    ): string | null {
+    public transform(countryIsoCode: IsoCode): string;
+    public transform(countryIsoCode: IsoCode | undefined): string | null;
+    public transform(countryIsoCode?: IsoCode | null): string | null;
+    public transform(countryIsoCode?: IsoCode | null): string | null {
         if (!countryIsoCode) {
             return null;
         }
diff --git a/projects/i18n/types/language-names.ts b/projects/i18n/types/language-names.ts
index 9f935733fb1fd..de81ac6ca69c1 100644
--- a/projects/i18n/types/language-names.ts
+++ b/projects/i18n/types/language-names.ts
@@ -1,4 +1,6 @@
-export type TuiLanguageName =
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
+
+export type TuiLanguageName = TuiLooseUnion<
     | 'belarusian'
     | 'chinese'
     | 'dutch'
@@ -18,4 +20,4 @@ export type TuiLanguageName =
     | 'turkish'
     | 'ukrainian'
     | 'vietnamese'
-    | (Record<never, never> & string);
+>;
diff --git a/projects/kit/components/badged-content/badged-content.directive.ts b/projects/kit/components/badged-content/badged-content.directive.ts
index 76343c37a799e..ba6b002bc32c4 100644
--- a/projects/kit/components/badged-content/badged-content.directive.ts
+++ b/projects/kit/components/badged-content/badged-content.directive.ts
@@ -1,4 +1,5 @@
 import {Directive, Input} from '@angular/core';
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
 
 @Directive({
     standalone: true,
@@ -6,5 +7,5 @@ import {Directive, Input} from '@angular/core';
 })
 export class TuiBadgedContentDirective {
     @Input()
-    public tuiSlot: 'bottom' | 'top' | (Record<never, never> & string) = 'top';
+    public tuiSlot: TuiLooseUnion<'bottom' | 'top'> = 'top';
 }
diff --git a/projects/layout/components/app-bar/app-bar.directive.ts b/projects/layout/components/app-bar/app-bar.directive.ts
index eb9e7059994b5..391bb75b77b48 100644
--- a/projects/layout/components/app-bar/app-bar.directive.ts
+++ b/projects/layout/components/app-bar/app-bar.directive.ts
@@ -1,4 +1,5 @@
 import {Directive, Input} from '@angular/core';
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
 
 @Directive({
     standalone: true,
@@ -6,5 +7,5 @@ import {Directive, Input} from '@angular/core';
 })
 export class TuiAppBarDirective {
     @Input()
-    public tuiSlot: 'left' | 'right' | (Record<never, never> & string) = 'left';
+    public tuiSlot: TuiLooseUnion<'left' | 'right'> = 'left';
 }
diff --git a/projects/layout/components/block-status/block-status.directive.ts b/projects/layout/components/block-status/block-status.directive.ts
index 4c1cf63a59be7..5614e5dc86e5f 100644
--- a/projects/layout/components/block-status/block-status.directive.ts
+++ b/projects/layout/components/block-status/block-status.directive.ts
@@ -1,4 +1,5 @@
 import {Directive, Input} from '@angular/core';
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
 
 @Directive({
     standalone: true,
@@ -6,5 +7,5 @@ import {Directive, Input} from '@angular/core';
 })
 export class TuiBlockStatusDirective {
     @Input()
-    public tuiSlot: 'action' | 'top' | (Record<never, never> & string) = 'top';
+    public tuiSlot: TuiLooseUnion<'action' | 'top'> = 'top';
 }
diff --git a/projects/legacy/directives/wrapper/wrapper.directive.ts b/projects/legacy/directives/wrapper/wrapper.directive.ts
index 7ac1026492225..af1cb7e8334a8 100644
--- a/projects/legacy/directives/wrapper/wrapper.directive.ts
+++ b/projects/legacy/directives/wrapper/wrapper.directive.ts
@@ -1,4 +1,5 @@
 import {Directive, Input} from '@angular/core';
+import type {TuiLooseUnion} from '@taiga-ui/cdk/types';
 import type {TuiInteractiveState} from '@taiga-ui/core/types';
 
 /**
@@ -46,10 +47,7 @@ export class TuiWrapperDirective {
         return this.focus && !this.disabled;
     }
 
-    protected get interactiveState():
-        | TuiInteractiveState
-        | (Record<never, never> & string)
-        | null {
+    protected get interactiveState(): TuiLooseUnion<TuiInteractiveState> | null {
         if (this.disabled) {
             return 'disabled';
         }