[Suspense] Document what activates a boundary and define Suspense-enabled frameworks

src/content/reference/react-dom/server/renderToPipeableStream.md

@@ -292,9 +292,9 @@ Streaming does not need to wait for React itself to load in the browser, or for
 
 Suspense **does not** detect when data is fetched inside an Effect or event handler.
 
-The exact way you would load data in the `Posts` component above depends on your framework. If you use a Suspense-enabled framework, you'll find the details in its data fetching documentation.
+The exact way you would load data in the `Posts` component above depends on your framework. If you use a [Suspense-enabled framework](/reference/react/Suspense#what-is-a-suspense-enabled-framework), you'll find the details in its data fetching documentation.
 
-Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
+Without a framework, you can read a Promise with [`use`](/reference/react/use) as long as the Promise is [cached so the same instance is reused across renders.](/reference/react/use#caching-promises-for-client-components)
 
 </Note>
 

src/content/reference/react-dom/server/renderToReadableStream.md

@@ -291,9 +291,9 @@ Streaming does not need to wait for React itself to load in the browser, or for
 
 Suspense **does not** detect when data is fetched inside an Effect or event handler.
 
-The exact way you would load data in the `Posts` component above depends on your framework. If you use a Suspense-enabled framework, you'll find the details in its data fetching documentation.
+The exact way you would load data in the `Posts` component above depends on your framework. If you use a [Suspense-enabled framework](/reference/react/Suspense#what-is-a-suspense-enabled-framework), you'll find the details in its data fetching documentation.
 
-Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
+Without a framework, you can read a Promise with [`use`](/reference/react/use) as long as the Promise is [cached so the same instance is reused across renders.](/reference/react/use#caching-promises-for-client-components)
 
 </Note>
 

src/content/reference/react-dom/static/prerender.md

@@ -283,9 +283,9 @@ Imagine that `<Posts />` needs to load some data, which takes some time. Ideally
 
 Suspense **does not** detect when data is fetched inside an Effect or event handler.
 
-The exact way you would load data in the `Posts` component above depends on your framework. If you use a Suspense-enabled framework, you'll find the details in its data fetching documentation.
+The exact way you would load data in the `Posts` component above depends on your framework. If you use a [Suspense-enabled framework](/reference/react/Suspense#what-is-a-suspense-enabled-framework), you'll find the details in its data fetching documentation.
 
-Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
+Without a framework, you can read a Promise with [`use`](/reference/react/use) as long as the Promise is [cached so the same instance is reused across renders.](/reference/react/use#caching-promises-for-client-components)
 
 </Note>
 

src/content/reference/react-dom/static/prerenderToNodeStream.md

@@ -284,9 +284,9 @@ Imagine that `<Posts />` needs to load some data, which takes some time. Ideally
 
 Suspense **does not** detect when data is fetched inside an Effect or event handler.
 
-The exact way you would load data in the `Posts` component above depends on your framework. If you use a Suspense-enabled framework, you'll find the details in its data fetching documentation.
+The exact way you would load data in the `Posts` component above depends on your framework. If you use a [Suspense-enabled framework](/reference/react/Suspense#what-is-a-suspense-enabled-framework), you'll find the details in its data fetching documentation.
 
-Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
+Without a framework, you can read a Promise with [`use`](/reference/react/use) as long as the Promise is [cached so the same instance is reused across renders.](/reference/react/use#caching-promises-for-client-components)
 
 </Note>
 

src/content/reference/react/Activity.md

@@ -763,9 +763,9 @@ Pre-rendering components with hidden Activity boundaries is a powerful way to re
 
 Activity **does not** detect data that is fetched inside an Effect.
 
-The exact way you would load data in the `Posts` component above depends on your framework. If you use a Suspense-enabled framework, you'll find the details in its data fetching documentation.
+The exact way you would load data in the `Posts` component above depends on your framework. If you use a [Suspense-enabled framework](/reference/react/Suspense#what-is-a-suspense-enabled-framework), you'll find the details in its data fetching documentation.
 
-Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
+Without a framework, you can read a Promise with [`use`](/reference/react/use) as long as the Promise is [cached so the same instance is reused across renders.](/reference/react/use#caching-promises-for-client-components)
 
 </Note>
 

src/content/reference/react/Suspense.md

@@ -29,6 +29,7 @@ title: <Suspense>
 
 #### Caveats {/*caveats*/}
 
+- Suspense does not detect when data is fetched inside an Effect or event handler. It only activates for the [resources listed below.](#what-activates-a-suspense-boundary)
 - React does not preserve any state for renders that got suspended before they were able to mount for the first time. When the component has loaded, React will retry rendering the suspended tree from scratch.
 - If Suspense was displaying content for the tree, but then it suspended again, the `fallback` will be shown again unless the update causing it was caused by [`startTransition`](/reference/react/startTransition) or [`useDeferredValue`](/reference/react/useDeferredValue).
 - If React needs to hide the already visible content because it suspended again, it will clean up [layout Effects](/reference/react/useLayoutEffect) in the content tree. When the content is ready to be shown again, React will fire the layout Effects again. This ensures that Effects measuring the DOM layout don't try to do this while the content is hidden.
@@ -203,19 +204,27 @@ async function getAlbums() {
 
 </Sandpack>
 
-<Note>
+---
+
+### What activates a Suspense boundary {/*what-activates-a-suspense-boundary*/}
 
-**Only Suspense-enabled data sources will activate the Suspense component.** They include:
+A Suspense boundary displays its `fallback` while its content is loading, and it can also wait on other resources before revealing that content. The following activate a boundary:
 
-- Data fetching with Suspense-enabled frameworks like [Relay](https://relay.dev/docs/guided-tour/rendering/loading-states/) and [Next.js](https://nextjs.org/docs/app/building-your-application/routing/loading-ui-and-streaming#streaming-with-suspense)
-- Lazy-loading component code with [`lazy`](/reference/react/lazy)
-- Reading the value of a cached Promise with [`use`](/reference/react/use)
+- Lazy-loading component code with [`lazy`](/reference/react/lazy).
+- Reading a Promise with [`use`](/reference/react/use), including data streamed from [Server Components](/reference/rsc/server-components) and integrations from frameworks like [Relay](https://relay.dev/docs/guided-tour/rendering/loading-states/).
+- Loading a stylesheet rendered with [`<link rel="stylesheet">` and a `precedence` prop.](/reference/react-dom/components/link#special-rendering-behavior) React blocks the boundary until the stylesheet loads, up to a timeout.
+- Loading fonts. React blocks a streamed boundary until [`document.fonts.ready`](https://developer.mozilla.org/en-US/docs/Web/API/FontFaceSet/ready) resolves, up to a timeout. Fonts also block a [`<ViewTransition>`](/reference/react/ViewTransition) update.
+- Streaming a large boundary's HTML during server rendering. React reveals the content as the HTML arrives.
+- Loading an image, where the `src` blocks the boundary until the image loads. This behavior is not enabled by default. When enabled, an `onLoad` handler opts an image out, and images in a [`<ViewTransition>`](/reference/react/ViewTransition) update opt in automatically.
+- <ExperimentalBadge /> Performing CPU-bound render work inside a `<Suspense>` boundary marked with the `defer` prop.
+
+<Note>
 
-Suspense **does not** detect when data is fetched inside an Effect or event handler.
+#### What is a Suspense-enabled framework? {/*what-is-a-suspense-enabled-framework*/}
 
-The exact way you would load data in the `Albums` component above depends on your framework. If you use a Suspense-enabled framework, you'll find the details in its data fetching documentation.
+A *Suspense-enabled framework* integrates data fetching with Suspense, so that reading data in a component activates the nearest boundary. The exact way you load data in the `Albums` component above depends on your framework, and you'll find the details in its data fetching documentation.
 
-Suspense-enabled data fetching without the use of an opinionated framework is not yet supported. The requirements for implementing a Suspense-enabled data source are unstable and undocumented. An official API for integrating data sources with Suspense will be released in a future version of React.
+Without a framework, you can read a Promise with [`use`](/reference/react/use) as long as the Promise is [cached so the same instance is reused across renders.](/reference/react/use#caching-promises-for-client-components)
 
 </Note>
 

src/content/reference/react/use.md

@@ -472,7 +472,7 @@ function Albums() {
 }
 ```
 
-Instead, pass a Promise from a cache, a Suspense-enabled framework, or a Server Component:
+Instead, pass a Promise from a cache, a [Suspense-enabled framework](/reference/react/Suspense#what-is-a-suspense-enabled-framework), or a Server Component:
 
 ```js
 // ✅ fetchData reads the Promise from a cache.
@@ -538,7 +538,7 @@ The `fetchData` function returns the same Promise each time it's called with the
 
 <Note>
 
-The way you cache Promises depends on the framework you use with Suspense. Frameworks typically provide built-in caching mechanisms. If you don't use a framework, you can use a simple module-level cache like the one above, or a [Suspense-enabled data source](/reference/react/Suspense#displaying-a-fallback-while-content-is-loading).
+The way you cache Promises depends on the framework you use with Suspense. Frameworks typically provide built-in caching mechanisms. If you don't use a framework, you can use a simple module-level cache like the one above, or a [Suspense-enabled data source](/reference/react/Suspense#what-is-a-suspense-enabled-framework).
 
 </Note>
 

src/content/reference/react/useDeferredValue.md

@@ -86,7 +86,7 @@ During updates, the <CodeStep step={2}>deferred value</CodeStep> will "lag behin
 
 <Note>
 
-This example assumes you use a Suspense-enabled data source:
+This example assumes you use a [Suspense-enabled data source](/reference/react/Suspense#what-is-a-suspense-enabled-framework):
 
 - Data fetching with Suspense-enabled frameworks like [Relay](https://relay.dev/docs/guided-tour/rendering/loading-states/) and [Next.js](https://nextjs.org/docs/app/getting-started/fetching-data#with-suspense)
 - Lazy-loading component code with [`lazy`](/reference/react/lazy)