#94 #96 #99

Author: donmendelson

v2-0-RC2/doc/01Introduction.md

@@ -185,4 +185,6 @@ Representation of dates and times
 Securities and related financial instruments - Codes for exchanges and
 market identification (MIC)
 
-[W3C XML Schema version 1.1](https://www.w3.org/TR/2006/REC-xml11-20060816/)
+*W3C XML Schema version 1.0* [Part 1](https://www.w3.org/TR/xmlschema-1/) [Part 2](https://www.w3.org/TR/xmlschema-2/)
+
+[W3C XML Inclusions (XInclude) Version 1.0](https://www.w3.org/TR/xinclude/)

v2-0-RC2/doc/04MessageSchema.md

@@ -5,7 +5,8 @@ XML schema for SBE message schemas
 ---------
 See [sbe.xsd](../resources/sbe.xsd) for the normative XML Schema Definition (XSD) for SBE.
 
-The SBE schema is defined with W3C XML Schema Definition Language (XSD) version 1.1.
+The SBE schema is defined with W3C XML Schema Definition Language (XSD) version 1.0. (XSD version 1.1 was standardized.
+However, since it is not supported by all XML processors, the SBE XSD is constrained to features of version 1.0.)
 
 
 XML namespace
@@ -82,8 +83,17 @@ Data encodings
 
 ### Encoding sets 
 
-The `<types>` element contains one or more sets of data encodings used
-for messages within the schema.
+A `<types>` element contains a set of data encodings used by messages within a schema. A message schema may have multiple
+instances of `<types>`, if desired, to organize them by categories. Each `<types>` element may have an associated `package` name.
+
+**`<types>` element attribute**
+
+| Schema attribute | Description                                                                                      | XML type           | Usage                  | Valid values                                                                 |
+|------------------|--------------------------------------------------------------------------------------------------|--------------------|------------------------|------------------------------------------------------------------------------|
+| package          | Overrides package of messageSchema                                                                     | string             | optional               | Should be unique between counterparties but no naming convention is imposed. |
+
+The `<types>` element has attribute `xml:base` to support inclusion from a separate XML file using the XInclude mechanism.
+Thus, common encoding types may be shared across multiple SBE message schemas.
 
 Within each set, an unbound number of encodings will be listed in any
 sequence:
@@ -371,13 +381,24 @@ Multi-value choice example, The choice is encoded as a bitset.
 </set>
 ```
 
-Message template
+Message templates
 --------------------------------------------------------------------------------------------------------------
 
-To define a message type, add a `<message>` element to the root element
-of the XML document, `<messageSchema>`.
+A `<messages>` element contains a set of message templates. A message schema may have multiple
+instances of `<messages>`, if desired, to organize them by categories. Each `<messages>` element may have an associated `package` name.
+
+**`<messages>` element attribute**
+
+| Schema attribute | Description                                                                                      | XML type           | Usage                  | Valid values                                                                 |
+|------------------|--------------------------------------------------------------------------------------------------|--------------------|------------------------|------------------------------------------------------------------------------|
+| package          | Overrides package of messageSchema                                                                     | string             | optional               | Should be unique between counterparties but no naming convention is imposed. |
+
+The `<messages>` element has attribute `xml:base` to support inclusion from a separate XML file using the XInclude mechanism.
+Thus, common message templates may be shared across multiple SBE message schemas.
+
+To define a message type, add a `<message>` element to `<messages>`.
 
-The `name` and `id` attributes are required. The first is a display name for
+The `name` and `id` attributes of `<message>` are required. The first is a display name for
 a message, while the latter is a unique numeric identifier, commonly
 called template ID.