diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml
index acf6ff74f98..1c0f39e11ec 100644
--- a/doc/src/sgml/xfunc.sgml
+++ b/doc/src/sgml/xfunc.sgml
@@ -3628,7 +3628,7 @@ CREATE FUNCTION make_array(anyelement) RETURNS anyarray
       Add-ins can reserve shared memory on server startup.  To do so, the
       add-in's shared library must be preloaded by specifying it in
       <xref linkend="guc-shared-preload-libraries"/><indexterm><primary>shared_preload_libraries</primary></indexterm>.
-      The shared library should register callbacks in its
+      The shared library should register callbacks in
       its <function>_PG_init</function> function, which then get called at the
       right stages of the system startup to initialize the shared memory.
       Here is an example:
@@ -3692,11 +3692,11 @@ my_shmem_init(void *arg)
 }
 
 </programlisting>
-      The <function>request_fn</function> callback is called during system
+      The <function>shmem_request_fn</function> callback is called during system
       startup, before the shared memory has been allocated. It should call
       <function>ShmemRequestStruct()</function> to register the add-in's
       shared memory needs. Note that <function>ShmemRequestStruct()</function>
-      doesn'' immediately allocate or initialize the memory, it merely
+      doesn't immediately allocate or initialize the memory, it merely
       registers the space to be allocated later in the startup sequence.  When
       the memory is allocated, it is initialized to zero.  To any more complex
       initialization, set the <function>init_fn()</function> callback, which
@@ -3726,7 +3726,7 @@ my_shmem_init(void *arg)
       libraries that are not specified in
       <xref linkend="guc-shared-preload-libraries"/><indexterm><primary>shared_preload_libraries</primary></indexterm>.
       However, after startup the allocation can fail if there is not enough
-      shared memory available. The system reserves a somes memory for
+      shared memory available. The system reserves some memory for
       allocations after startup, but that reservation is small.
      </para>
      <para>
@@ -3739,8 +3739,8 @@ my_shmem_init(void *arg)
       When <function>RegisterShmemCallbacks()</function> is called after
       startup, it will immediately call the appropriate callbacks, depending
       on whether the requested memory areas were already initialized by
-      another backend. The callbacks will be held while holding an internal
-      lock, which prevents concurrent two backends from initializating the
+      another backend. The callbacks will be called while holding an internal
+      lock, which prevents multiple backends from initializating the
       memory area concurrently.
      </para>
     </sect3>