Here's the link to the WHO report: http://monographs.iarc.fr/ENG/Monographs/vol112/index.php
From page 22 of the preamble: the category Group 2A "is used when there is limited evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals".
http://monographs.iarc.fr/ENG/Monographs/vol112/mono112-F06....
https://en.wikipedia.org/wiki/List_of_IARC_Group_2A_carcinog...
Something may also be classified as 2A when "Exceptionally, an agent may be classified in this group solely on the basis of limited evidence of carcinogenicity in humans." Which I think Glyphosate falls into.