The Service Config User role allows a user to access the OCLC Service Configuration site, https://worldcat.org/config, using their OCLC Services Account. This role is necessary to edit the WorldCat Registry and other OCLC settings. Here's what you can do there: OCLC Service Configuration guide
More information here: OCLC Service Configuration roles
How can I update my library address or name in the WorldCat Registry?