Ok, sorry, please disregard found diffing the source packages:
diff -ruN tzdata-2016j/southamerica tzdata-2017b/southamerica --- tzdata-2016j/southamerica 2016-08-23 20:52:10.000000000 -0300 +++ tzdata-2017b/southamerica 2017-01-20 01:24:25.000000000 -0200 ... +# These tables use numeric abbreviations like -03 and -0330 for +# integer hour and minute UTC offsets. Although earlier editions used +# alphabetic time zone abbreviations, these abbreviations were +# invented and did not reflect common practice. ... @@ -978,119 +950,119 @@ # In the north a very small part from the river Javary (now Jari I guess, # the border with Amapá) to the Amazon, then to the Xingu. Zone America/Belem -3:13:56 - LMT 1914 - -3:00 Brazil BR%sT 1988 Sep 12 - -3:00 - BRT + -3:00 Brazil -03/-02 1988 Sep 12 + -3:00 - -03