From 82aecd4e929e3d49cf7e3698a38ebdf60382775e Mon Sep 17 00:00:00 2001
From: Yongjing Zhang <zhangyongjing@huawei.com>
Date: Wed, 18 Jul 2018 11:08:54 -0400
Subject: [PATCH] give more intro text in SDT_JSON.md to explain the transition
 from xml to json.

---
 SDT/schema4.0/docs/SDT_JSON.md | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/SDT/schema4.0/docs/SDT_JSON.md b/SDT/schema4.0/docs/SDT_JSON.md
index f48c352..0b6c66b 100644
--- a/SDT/schema4.0/docs/SDT_JSON.md
+++ b/SDT/schema4.0/docs/SDT_JSON.md
@@ -1,4 +1,8 @@
-JSON serialization is supported since SDT4.0 as it's very popular nowadays in the developers' communities, especially in the context of RESTful implementation. JSON is more concise and human-readable comparing to XML, but has less capability of formal schema definition and validation (such as the XML Schema as defined in [domain.xsd](SDT/schema4.0/src/domain.xsd)). 
+When SDT was introduced, XML was the favorite encoding format for schemas. Since then, JSON became more popular in the developers' communities, especially in the context of RESTful implementation. 
+
+JSON is more concise and human-readable comparing to XML, but has less capability of formal schema definition and validation (such as the XML Schema as defined in [domain.xsd](SDT/schema4.0/src/domain.xsd)). 
+
+For these reasons, JSON serialization is supported since SDT4.0.
 
 There are some open tools such as [JSON Schema](http://json-schema.org/) that might be useful for describing and validating the JSON serialization of SDT, but it's not yet a formal standard and is still under development.
 
-- 
GitLab