There are currently 4 directories in common/testData. Each has a _readme.txt with copyright information for all the files in that directory. The format of the files in the directory is either in the individual data files, or in the _readme.txt
localeIdentifiers — generated data for use by clients
segmentation — curated data used in CLDR testing, and can be used by clients
transforms — curated data used in CLDR testing, and can be used by clients
units — generated data for use by clients
To produce the generated data (units/ and localeIdentifiers/):
run TestUnits with -DTestUnits:GENERATE_TESTS, and copy the relevant sections into the two files as per generated instructions. Compare, verify, and commit.
run GenerateLocaleIDTestData.java. It will generate the file in place.
run TestLocaleDisplay.java -v. Copy the section under TestLocaleDisplay into the file (after the header).