ETO has many unique identifiers which makes reporting easy! You will see these identifiers in many Standard and Custom universe.
Participant Site ID / Client ID: Sometimes seen as PSID and CLID are different names for the same backend identifier. This is primarily used to map participant data to demographic and sometimes Touchpoint data. This is also the ID that commonly matches a participants Case Number. PSID is unique per site, so if a participant is enrolled in more than one site, they will have a unique PSID per site. Their case number may or may not be unique per site.
Participant Site ID can be found in the UI by following this article.
Match PSID and Case Number following these instructions.
Subject ID: In ETO Results, Subject Identifier is used as the primary identifier to relate TouchPoint responses to subjects in ETO. Since TouchPoints can be for multiple types of subjects, a unique Subject Identifier is created in order to avoid overlap between identifiers specific to each subject. Subject ID is separate and unique from PSID.
Learn more about Subject ID here.
Participant Enterprise ID / Global Unique ID: Enterprise ID or GUID refers to the identifier linking participants across multiple sites in ETO. A participant may exist in multiple sites meaning they have multiple PSIDs, but if they all have the same Enterprise ID, ETO can recognize they are the same participant.
Learn more about Enterprise clients and duplicates here.