This research explores the relationship between selfpresentation and perception by others as manifested explicitly through the use of tags in a people tagging system. The study provides insights relevant for the organizational context since it is based on a system implemented within IBM. We developed a detailed codebook and used it to categorize 9,506 tags assigned to a sample of taggers. Our analysis examines the use of self tags versus social tags (assigned by others) across different categories and sub-categories. While overlap exists, self tags tend to be more factual describing technology expertise, social tags augment the individual tags by adding a personal dimension. Copyright 2012 ACM.