Clarify valid catch all routes

docs/api-reference/next/link.md

@@ -99,7 +99,7 @@ function NavLink({ href, name }) {
 export default NavLink
 ```
 
-> **Note:** If you’re using [emotion](https://emotion.sh/)’s JSX pragma feature (`@jsx jsx`), you must use `passHref` even if you use an `<a>` tag directly.
+> **Note**: If you’re using [emotion](https://emotion.sh/)’s JSX pragma feature (`@jsx jsx`), you must use `passHref` even if you use an `<a>` tag directly.
 
 ## If the child is a function component
 

docs/api-routes/dynamic-api-routes.md

@@ -26,6 +26,8 @@ API Routes can be extended to catch all paths by adding three dots (`...`) insid
 
 - `pages/api/post/[...slug].js` matches `/api/post/a`, but also `/api/post/a/b`, `/api/post/a/b/c` and so on.
 
+> **Note**: `slug` is only a name, it can be anything, a catch all API route is formed by having the brackets used by dynamic API routes, the three dots and the name (`[...param]`).
+
 Matched parameters will be sent as a query parameter (`slug` in the example) to the page, and it will always be an array, so, the path `/api/post/a` will have the following `query` object:
 
 ```json

docs/routing/dynamic-routes.md

@@ -69,6 +69,8 @@ Dynamic routes can be extended to catch all paths by adding three dots (`...`) i
 
 - `pages/post/[...slug].js` matches `/post/a`, but also `/post/a/b`, `/post/a/b/c` and so on.
 
+> **Note**: `slug` is only a name, it can be anything, a catch all route is formed by having the brackets used by dynamic routes, and the three dots, and the page name (`[...param]`).
+
 Matched parameters will be sent as a query parameter (`slug` in the example) to the page, and it will always be an array, so, the path `/post/a` will have the following `query` object:
 
 ```json