2017 Topps Baseball Forum

While I cannot find any reference to it, the 2017 Topps Roberto Perez card should be labled as such. The back states he homered in his initial postseason AB in the "ALCS". It should say "ALDS" as he homered in game 1 in 2016 against Boston. Would/should this be identified here despite no other reference in the hobby?

Assuming your information is correct (and I assume it is), then yes, it is an error and almost certainly uncorrected. As such, it should be listed in the notes for the card.  Small errors like these are both easy to make and easy for the community to overlook, so it's not surprising it hasn't been mentioned elsewhere in the hobby.

According to https://www.baseball-reference.com/players/p/perezro02.shtml he didn't hit any HR in the ALCS. The only HR he hit in the post season was in the ALDS (1) and the WS (2). Someone made the changes already.