diff --git a/docs/libcurl/opts/CURLMOPT_SOCKETFUNCTION.md b/docs/libcurl/opts/CURLMOPT_SOCKETFUNCTION.md
index 411b856e93..2774ccbfc7 100644
--- a/docs/libcurl/opts/CURLMOPT_SOCKETFUNCTION.md
+++ b/docs/libcurl/opts/CURLMOPT_SOCKETFUNCTION.md
@@ -22,13 +22,14 @@ CURLMOPT_SOCKETFUNCTION - callback informed about what to wait for
 ~~~c
 #include <curl/curl.h>
 
-int socket_callback(CURL *easy,      /* easy handle */
-                    curl_socket_t s, /* socket */
-                    int what,        /* describes the socket */
-                    void *clientp,   /* private callback pointer */
-                    void *socketp);  /* private socket pointer */
+int socket_callback(CURL *easy,
+                    curl_socket_t socket,
+                    int what,
+                    void *clientp,
+                    void *socketp);
 
-CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETFUNCTION, socket_callback);
+CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETFUNCTION,
+                            socket_callback);
 ~~~
 
 # DESCRIPTION
@@ -36,12 +37,12 @@ CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETFUNCTION, socket_callb
 Pass a pointer to your callback function, which should match the prototype
 shown above.
 
-When the curl_multi_socket_action(3) function is called, it uses this
-callback to inform the application about updates in the socket (file
-descriptor) status by doing none, one, or multiple calls to the
-**socket_callback**. The callback function gets status updates with changes
-since the previous time the callback was called. If the given callback pointer
-is set to NULL, no callback is called.
+When the curl_multi_socket_action(3) function is called, it uses this callback
+to inform the application about updates in the socket (file descriptor) status
+by doing none, one, or multiple calls to the **socket_callback**. The callback
+function gets status updates with changes since the previous time the callback
+was called. If the given callback pointer is set to NULL, no callback is
+called.
 
 libcurl then expects the application to monitor the sockets for the specific
 activities and tell libcurl again when something happens on one of them. Tell
@@ -52,18 +53,23 @@ This may even happen after all transfers are done and is *likely* to
 happen *during* a call to curl_multi_cleanup(3) when cached connections
 are shut down.
 
+libcurl may use a number of internal file descriptors for name resolving,
+Happy Eyeballs racing, internal communication and more, in addition to the
+main sockets used for network transfers. All of those file descriptors might
+get passed to this callback as "sockets".
+
 # CALLBACK ARGUMENTS
 
-*easy* identifies the specific transfer for which this update is related.
+**easy** identifies the specific transfer for which this update is related.
 Since this callback manages a whole multi handle, an application should not
 make assumptions about which particular handle that is passed here. It might
 even be an internal easy handle that the application did not add itself.
 
-*s* is the specific socket this function invocation concerns. If the
-**what** argument is not CURL_POLL_REMOVE then it holds information about
-what activity on this socket the application is supposed to
-monitor. Subsequent calls to this callback might update the **what** bits
-for a socket that is already monitored.
+**socket** is the specific socket this function invocation concerns. If the
+**what** argument is not CURL_POLL_REMOVE then it holds information about what
+activity on this socket the application is supposed to monitor. Subsequent
+calls to this callback might update the **what** bits for a socket that is
+already monitored.
 
 The socket callback should return 0 on success, and -1 on error. If this
 callback returns error, **all** transfers currently in progress in this
@@ -73,8 +79,8 @@ multi handle are aborted and made to fail.
 
 **socketp** is set with curl_multi_assign(3) or NULL.
 
-The **what** parameter informs the callback on the status of the given
-socket. It can hold one of these values:
+The **what** parameter informs the callback on the status of the given socket.
+It can hold one of these values:
 
 ## CURL_POLL_IN
 
@@ -94,6 +100,14 @@ writable.
 The specified socket/file descriptor is no longer used by libcurl for any
 active transfer. It might soon be added again.
 
+When a socket is given a CURL_POLL_REMOVE value, it might be because libcurl
+is going to close it, but it might also mean that it does not need any more
+monitoring for the moment. An application cannot assume either. The same
+socket might appear soon in a call asking for monitoring again.
+
+A socket that is removed like this loses its assigned pointer as set with
+curl_multi_assign(3).
+
 # DEFAULT
 
 NULL (no callback)