Add appendix to data classification extension

See cloudevents#1317

Signed-off-by: Doug Davis <[email protected]>

cloudevents/extensions/data-classification.md

@@ -53,7 +53,7 @@ is being used.
 
 - Type: `String`
 - Description: Data category of the event payload within the context of a
-  `dataregulation` and `dataclassification`. For GDPR personal data typical  
+  `dataregulation` and `dataclassification`. For GDPR personal data typical
   labels are: `non-sensitive`, `standard`, `sensitive`, `special-category`. For
   US personal data this could be: `sensitive-pii`, `non-sensitive-pii`,
   `non-pii`. And for personal health information under HIPAA: `phi`.
@@ -92,4 +92,19 @@ Examples where data classification of events can be useful are:
   auditing and access policies based upon classification.
 - When an event payload is subjected to regulation and therefore retention
   policies apply. For example, having event retention policies based upon data
-  classification or to enable automated data purging of durable topics.
+  classification or to enable automated data purging of durable topics.
+
+## Appendix: Data Protection and Privacy Regulations
+
+For reference purposes, a catalog of common data protection and privacy
+regulation and abbreviations is availble from [UNCTAD
+(United Nations Conference on Trade and
+Development)](https://unctad.org/page/data-protection-and-privacy-legislation-worldwide),
+under the `DOWNLOAD FULL DATA` button ([direct
+link](https://unctad.org/system/files/information-document/DP.xlsx)). Others
+might exist.
+
+Some examples include:
+- `GDPR` - General Data Protection Regulation, Europe
+- `HIPAA` - Health Insurance Portability and Accountability Act, United States
+- `NDPR` - Nigeria Data Protection Regulation, Nigeria