diff --git a/xml/cl.xml b/xml/cl.xml
index d6cd517b..b0907351 100644
--- a/xml/cl.xml
+++ b/xml/cl.xml
@@ -463,6 +463,66 @@ server's OpenCL/api-docs repository.
     CL_SVM_CAPABILITY_CONCURRENT_ATOMIC_ACCESS_KHR | \
     CL_SVM_CAPABILITY_INDIRECT_ACCESS_KHR)</type>
 
+        <type category="funcpointer" name="cl_free_svm_callback">
+            <proto><type>void</type></proto>
+            <param><type>cl_command_queue</type>            <name>queue</name></param>
+            <param><type>cl_uint</type>                     <name>num_svm_pointers</name></param>
+            <param><type>void</type>*                       <name>svm_pointers</name>[]</param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_context_error_callback">
+            <proto><type>void</type></proto>
+            <param>const <type>char</type>*                 <name>errinfo</name></param>
+            <param>const <type>void</type>*                 <name>private_info</name></param>
+            <param><type>size_t</type>                      <name>cb</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_context_destruction_callback">
+            <proto><type>void</type></proto>
+            <param><type>cl_context</type>                  <name>context</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_mem_object_destruction_callback">
+            <proto><type>void</type></proto>
+            <param><type>cl_mem</type>                      <name>memobj</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_program_callback">
+            <proto><type>void</type></proto>
+            <param><type>cl_program</type>                  <name>program</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_program_destruction_callback">
+            <proto><type>void</type></proto>
+            <param><type>cl_program</type>                  <name>program</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_event_status_change_callback">
+            <proto><type>void</type></proto>
+            <param><type>cl_event</type>                    <name>event</name></param>
+            <param><type>cl_int</type>                      <name>event_command_status</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_native_kernel_callback">
+            <proto><type>void</type></proto>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
+        <type category="funcpointer" name="cl_printf_callback">
+            <proto><type>void</type></proto>
+            <param>const <type>char</type>*                 <name>buffer</name></param>
+            <param><type>size_t</type>                      <name>len</name></param>
+            <param><type>size_t</type>                      <name>complete</name></param>
+            <param><type>void</type>*                       <name>user_data</name></param>
+        </type>
+
     </types>
 
     <!-- SECTION: OpenCL enumerant (token) definitions. -->
@@ -2948,7 +3008,7 @@ server's OpenCL/api-docs repository.
             <param><type>cl_command_queue</type>           <name>command_queue</name></param>
             <param><type>cl_uint</type>                    <name>num_svm_pointers</name></param>
             <param><type>void</type>*                      <name>svm_pointers</name>[]</param>
-            <param>void (CL_CALLBACK*                      <name>pfn_free_func</name>)(cl_command_queue queue, cl_uint num_svm_pointers, void * svm_pointers[], void *user_data)</param>
+            <param><type>cl_free_svm_callback</type>       <name>pfn_free_func</name></param>
             <param><type>void</type>*                      <name>user_data</name></param>
             <param><type>cl_uint</type>                    <name>num_events_in_wait_list</name></param>
             <param>const <type>cl_event</type>*            <name>event_wait_list</name></param>
@@ -3596,7 +3656,7 @@ server's OpenCL/api-docs repository.
             <param>const <type>cl_context_properties</type>*            <name>properties</name></param>
             <param><type>cl_uint</type>                                 <name>num_devices</name></param>
             <param>const <type>cl_device_id</type>*                     <name>devices</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(const char* errinfo, const void* private_info, size_t cb, void* user_data)</param>
+            <param><type>cl_context_error_callback</type>               <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
             <param><type>cl_int</type>*                                 <name>errcode_ret</name></param>
         </command>
@@ -3604,7 +3664,7 @@ server's OpenCL/api-docs repository.
             <proto><type>cl_context</type>                              <name>clCreateContextFromType</name></proto>
             <param>const <type>cl_context_properties</type>*            <name>properties</name></param>
             <param><type>cl_device_type</type>                          <name>device_type</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(const char* errinfo, const void* private_info, size_t cb, void* user_data)</param>
+            <param><type>cl_context_error_callback</type>               <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
             <param><type>cl_int</type>*                                 <name>errcode_ret</name></param>
         </command>
@@ -3627,7 +3687,7 @@ server's OpenCL/api-docs repository.
         <command suffix="CL_API_SUFFIX__VERSION_3_0">
             <proto><type>cl_int</type>                                  <name>clSetContextDestructorCallback</name></proto>
             <param><type>cl_context</type>                              <name>context</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_context context, void* user_data)</param>
+            <param><type>cl_context_destruction_callback</type>         <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_2_0">
@@ -3750,13 +3810,13 @@ server's OpenCL/api-docs repository.
         <command suffix="CL_API_SUFFIX__VERSION_1_1">
             <proto><type>cl_int</type>                                  <name>clSetMemObjectDestructorCallback</name></proto>
             <param><type>cl_mem</type>                                  <name>memobj</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_mem memobj, void* user_data)</param>
+            <param><type>cl_mem_object_destruction_callback</type>      <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_1_0">
             <proto><type>cl_int</type>                                  <name>clSetMemObjectDestructorAPPLE</name></proto>
             <param><type>cl_mem</type>                                  <name>memobj</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_mem memobj, void* user_data)</param>
+            <param><type>cl_mem_object_destruction_callback</type>      <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_2_0">
@@ -3840,7 +3900,7 @@ server's OpenCL/api-docs repository.
             <param><type>cl_uint</type>                                 <name>num_devices</name></param>
             <param>const <type>cl_device_id</type>*                     <name>device_list</name></param>
             <param>const <type>char</type>*                             <name>options</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_program program, void* user_data)</param>
+            <param><type>cl_program_callback</type>                     <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_1_2">
@@ -3852,7 +3912,7 @@ server's OpenCL/api-docs repository.
             <param><type>cl_uint</type>                                 <name>num_input_headers</name></param>
             <param>const <type>cl_program</type>*                       <name>input_headers</name></param>
             <param>const <type>char</type>**                            <name>header_include_names</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_program program, void* user_data)</param>
+            <param><type>cl_program_callback</type>                     <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_1_2">
@@ -3863,14 +3923,14 @@ server's OpenCL/api-docs repository.
             <param>const <type>char</type>*                             <name>options</name></param>
             <param><type>cl_uint</type>                                 <name>num_input_programs</name></param>
             <param>const <type>cl_program</type>*                       <name>input_programs</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_program program, void* user_data)</param>
+            <param><type>cl_program_callback</type>                     <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
             <param><type>cl_int</type>*                                 <name>errcode_ret</name></param>
         </command>
         <command prefix="CL_API_PREFIX__VERSION_2_2_DEPRECATED" suffix="CL_API_SUFFIX__VERSION_2_2_DEPRECATED">
             <proto><type>cl_int</type>                                  <name>clSetProgramReleaseCallback</name></proto>
             <param><type>cl_program</type>                              <name>program</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_program program, void* user_data)</param>
+            <param><type>cl_program_destruction_callback</type>         <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_2_2">
@@ -4025,7 +4085,7 @@ server's OpenCL/api-docs repository.
             <proto><type>cl_int</type>                                  <name>clSetEventCallback</name></proto>
             <param><type>cl_event</type>                                <name>event</name></param>
             <param><type>cl_int</type>                                  <name>command_exec_callback_type</name></param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_notify</name>)(cl_event event, cl_int event_command_status, void *user_data)</param>
+            <param><type>cl_event_status_change_callback</type>         <name>pfn_notify</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
         </command>
         <command suffix="CL_API_SUFFIX__VERSION_1_0">
@@ -4279,7 +4339,7 @@ server's OpenCL/api-docs repository.
         <command suffix="CL_API_SUFFIX__VERSION_1_0">
             <proto><type>cl_int</type>                                  <name>clEnqueueNativeKernel</name></proto>
             <param><type>cl_command_queue</type>                        <name>command_queue</name></param>
-            <param>void (CL_CALLBACK*                                   <name>user_func</name>)(void*)</param>
+            <param><type>cl_native_kernel_callback</type>               <name>user_func</name></param>
             <param><type>void</type>*                                   <name>args</name></param>
             <param><type>size_t</type>                                  <name>cb_args</name></param>
             <param><type>cl_uint</type>                                 <name>num_mem_objects</name></param>
@@ -4308,7 +4368,7 @@ server's OpenCL/api-docs repository.
             <param><type>cl_command_queue</type>                        <name>command_queue</name></param>
             <param><type>cl_uint</type>                                 <name>num_svm_pointers</name></param>
             <param><type>void</type>*                                   <name>svm_pointers</name>[]</param>
-            <param>void (CL_CALLBACK*                                   <name>pfn_free_func</name>)(cl_command_queue queue, cl_uint num_svm_pointers, void* svm_pointers[], void* user_data)</param>
+            <param><type>cl_free_svm_callback</type>                    <name>pfn_free_func</name></param>
             <param><type>void</type>*                                   <name>user_data</name></param>
             <param><type>cl_uint</type>                                 <name>num_events_in_wait_list</name></param>
             <param>const <type>cl_event</type>*                         <name>event_wait_list</name></param>
@@ -4626,6 +4686,9 @@ server's OpenCL/api-docs repository.
             <type name="cl_profiling_info"/>
             <type name="cl_image_format"/>
             <type name="cl_buffer_region"/>
+            <type name="cl_context_error_callback"/>
+            <type name="cl_program_callback"/>
+            <type name="cl_native_kernel_callback"/>
         </require>
         <require comment="Constants">
             <enum name="CL_CHAR_BIT"/>
@@ -5132,6 +5195,8 @@ server's OpenCL/api-docs repository.
     <feature api="opencl" name="CL_VERSION_1_1" number="1.1" comment="OpenCL core API interface definitions">
         <require>
             <type name="cl_buffer_create_type"/>
+            <type name="cl_mem_object_destruction_callback"/>
+            <type name="cl_event_status_change_callback"/>
         </require>
         <require comment="Constants">
             <enum name="CL_NAN"/>
@@ -5398,6 +5463,7 @@ server's OpenCL/api-docs repository.
             <type name="cl_pipe_info"/>
             <type name="cl_sampler_properties"/>
             <type name="cl_kernel_exec_info"/>
+            <type name="cl_free_svm_callback"/>
         </require>
         <require comment="Error codes">
             <enum name="CL_INVALID_PIPE_SIZE"/>
@@ -5559,6 +5625,9 @@ server's OpenCL/api-docs repository.
     </feature>
 
     <feature api="opencl" name="CL_VERSION_2_2" number="2.2" comment="OpenCL core API interface definitions">
+        <require>
+            <type name="cl_program_destruction_callback"/>
+        </require>
         <require comment="Error codes">
             <enum name="CL_INVALID_SPEC_ID"/>
             <enum name="CL_MAX_SIZE_RESTRICTION_EXCEEDED"/>
@@ -5583,6 +5652,7 @@ server's OpenCL/api-docs repository.
             <type name="cl_mem_properties"/>
             <type name="cl_version"/>
             <type name="cl_name_version"/>
+            <type name="cl_context_destruction_callback"/>
         </require>
         <require comment="cl_device_atomic_capabilities - bitfield">
             <enum name="CL_DEVICE_ATOMIC_ORDER_RELAXED"/>
@@ -5864,6 +5934,9 @@ server's OpenCL/api-docs repository.
             <require>
                 <type name="CL/cl.h"/>
             </require>
+            <require condition="!defined(CL_VERSION_1_1)" comment="defined in CL.h for OpenCL 1.1 and newer">
+                <type name="cl_mem_object_destruction_callback"/>
+            </require>
             <require>
                 <command name="clSetMemObjectDestructorAPPLE"/>
             </require>
@@ -6062,6 +6135,9 @@ server's OpenCL/api-docs repository.
             <require>
                 <type name="CL/cl.h"/>
             </require>
+            <require>
+                <type name="cl_printf_callback"/>
+            </require>
             <require comment="cl_context_properties">
                 <enum name="CL_PRINTF_CALLBACK_ARM"/>
                 <enum name="CL_PRINTF_BUFFERSIZE_ARM"/>
@@ -6339,6 +6415,9 @@ server's OpenCL/api-docs repository.
                 <type name="cl_kernel_exec_info_arm"/>
                 <type name="cl_device_svm_capabilities_arm"/>
             </require>
+            <require condition="!defined(CL_VERSION_2_0)" comment="defined in CL.h for OpenCL 2.0 and newer">
+                <type name="cl_free_svm_callback"/>
+            </require>
             <require comment="cl_device_info">
                 <enum name="CL_DEVICE_SVM_CAPABILITIES_ARM"/>
             </require>
diff --git a/xml/registry.rnc b/xml/registry.rnc
index fb167f3d..d1b0273f 100644
--- a/xml/registry.rnc
+++ b/xml/registry.rnc
@@ -72,7 +72,7 @@ Types = element types {
 #   bitvalues - for a *Flags type, name of an enum definition that
 #       defines the valid values for parameters of that type
 #   category - if present, 'enum' indicates a matching <enums>
-#       block to generate an enumerated type for, and 'struct'
+#       block to generate an enumerated type for, and 'struct'/'function'
 #       causes special interpretation of the contents of the type
 #       tag including ... TBD ...
 #       Other allowed values are 'include', 'define', 'handle' and 'bitmask',
@@ -123,6 +123,9 @@ Types = element types {
 #       noautovalidity - tag stating that no automatic validity language should be generated
 #       values - comma-separated list of legal values, usually used only for sType enums
 #   <comment> - containing arbitrary text (unused)
+# For types with category 'function', contents should be one <proto> and zero or more <param>
+#   <proto> - contains a single <type> tag, indicating return value of function pointer
+#   <param> - like <param> tag in <command>
 #
 # *** There is a problem here: I am not sure how to represent the <type>
 # syntax where it may contain arbitrarily interleaved text, <type>, and
@@ -178,7 +181,18 @@ Type = element type {
                 } +
             } |
             element comment { text }
-        ) *
+        ) * |
+        (
+            element proto {
+                element type { TypeName }
+            } ,
+            element param {
+                mixed {
+                    element type { TypeName } ? ,
+                    element name { text } ?
+                }
+            } *
+        )
     )
 }