# RefSubject.FilteredTypeId

Runtime symbol identifying conditionally available Filtered values.

## Signatures

```ts
export declare const FilteredTypeId: unique symbol;
```

```ts
export type FilteredTypeId = typeof FilteredTypeId;
```

## Why

Provides stable runtime identity for Filtered values without relying on classes or a renderer.

## Ownership and lifetime

This declaration performs no acquisition and retains no resources. Implementations preserve
source errors, services, and lifetime.