-4. For ICU maintainers, don't forget to check in the new
- zoneinfo.txt (from its location at
- {path_to}/icu/source/data/misc/zoneinfo.txt) into CVS.
+### Following instructions for ICU maintainers only ###
+
+4. Obtain the current version of tzcodeYYYY.tar.gz from the FTP site to
+ this directory.
+
+5. Run make target "check-dump". This target extract makes the original
+ tzcode and compile the original tzdata with icu supplemental data
+ (icuzones). Then it makes zdump / icuzdump and dump all time
+ transitions for all ICU timezone to files under zdumpout / icuzdumpout
+ directory. When they produce different results, the target returns
+ the error.
+
+6. Don't forget to check in the new zoneinfo.txt (from its location at
+ {path_to}/icu/source/data/misc/zoneinfo.txt) into SVN.
+