Here's a discussion about the topic: http://forum.wordreference.com/showthread.php?t=29285 http://forum.wordreference.com/showthread.php?t=29285 Edit: Actually

Here's a discussion about the topic: http://forum.wordreference.com/showthread.php?t=29285 http://forum.wordreference.com/showthread.php?t=29285 Edit: Actually, it's not just an issue about the proper noun ending in "s", but the proper noun ("Consumer Reports") is actually using a plural noun, reports. For the case of making a plural possessive, most would agree that you just add an apostrophe without an additional "s" (s' rather than s's).