Hello
I’m new to OpenMRS and was able to download and start Reference Application 2.3.1 Standalone Edition from http://openmrs.org/download/. Now I want to clone this release from git. As I understand it should be on https://github.com/openmrs/openmrs-distro-referenceapplication/. Though cannot understand what branch/commit should I clone from, to get this released version source code?
Actually you should clone https://github.com/openmrs/openmrs-standalone
The standalone gets built using the standalone, the ref app is just distribution that is made up of several modules and the platform and there is almost no code you would want to look at in its github repo. If you wish to look at the source code, you need to look at that of the individual modules or the platform. You might need to know which feature whose code you wish to look at in order to determine the module or platform code to look at.
Forgive our inability to name our products in ways that humans can understand. 
You want to build the 2.3.1 version of Reference Application, which is a released product that is based on our Platform product along with several additional modules, as mentioned above. The pages at Reference Application dev environment setup - Documentation - OpenMRS Wiki and Developer How-To Launch a Local Instance of the Reference Application - Documentation - OpenMRS Wiki have some instructions to do so.
Standalone Edition of Reference Application is just a way of delivering the application & database in an “all-in-one” package to make it easy for people to run.
Thanks to all. Will try this route.