Merge pull request cf-convention#503 from larsbarring/issue-500

Appendix B: Added a **`conventions_string`** to the standard name xml file format definition

appb.adoc

@@ -25,20 +25,24 @@ Next is the **`standard_name_table`** itself, which is bracketed by the tags **`
 The content (delimited by the `<standard_name_table>` tags) consists of, in order,
 
 ----
+  <version_number>Version number here ... </version_number>
+  <conventions>Conventions string here ... </conventions> 
+  <last_modified>Datetime stamp here ... </last_modified>
   <institution>Name of institution here ... </institution>
   <contact>E-mail address of contact person ... </contact>
 ----
 
-followed by a sequence of **`entry`** elements which may optionally be followed by a sequence of **`alias`** elements.
+where the "Conventions string" is  composed of the fixed string **`CF-StandardNameTable-`** immediately followed by the version number.
+
+Next follows a sequence of **`entry`** elements which may optionally be followed by a sequence of **`alias`** elements.
 The **`entry`** and **`alias`** elements take the following forms:
 
 ----
   <entry id="an_id">
       Define the variable whose standard_name attribute has the value "an_id".
   </entry>
   <alias id="another_id">
-      Provide alias for a variable whose standard_name attribute has the
-        value "another_id".
+      Provide alias for a variable whose standard_name attribute has the value "another_id".
   </alias>
 ----
 
@@ -87,6 +91,8 @@ Each **`alias`** element contains a single element:
 ----
   <?xml version="1.0"?>
   <standard_name_table>
+    <version_number>83</version_number>
+    <conventions>CF-StandardNameTable-83</conventions>
     <institution>Program for Climate Model Diagnosis and Intercomparison</institution>
     <contact>[email protected]</contact>
     <entry id="surface_air_pressure">

history.adoc

@@ -7,6 +7,8 @@
 
 === Working version (most recent first)
 
+* {issues}500[Issue #500]: Appendix B: Added a **`conventions`** string to the standard name xml file format definition
+
 === Version 1.11 (05 December 2023)
 
 * {issues}481[Issue #481]: Introduce **`units_metadata`** attribute and clarify some other aspects of **`units`**