Suported OS for versions prior to 5.3

I still look after a number of sites who are running versions prior to 5.3, typically 3.8.1P

Invariably when they come to upgrade it involves an OS upgrade also

The normal Cloverleaf upgrade procedure is to run both the old and new Cloverleaf in parallel for a short period to confirm there are no upgrade issues

This invariably cause an issue because we need to upgrade to an OS that is supported for both version fo Cloverleaf

So would it be possible to post a table of supported OS for 3.8.1P