Hi David,
I've developed my own client using the Delphi/Pascal language.
Using Windows 2008 R2 SP1.
java version "1.8.0_112"
Java(TM) SE Runtime Environment (build 1.8.0_112-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.112-b15, mixed mode)
I also tested using curl like so:
curl -XPUT http://localhost:9200/Delphi
The error I got was:
{"error":{"root_cause":[{"type":"invalid_index_name_exception","reason":"Invalid index name [Delphi], must be lowercase","index_uuid":"na","index":"Delphi"}],"type":"invalid_index_name_exception","reason":"Invalid index name [Delphi], must be lowercase","index_uuid":"na","index":"Delphi"},"status":400}