Each group on a Unix system is identified by its group ID (GID), a number comprised between 0 and 65535. If two groups share the same GID, then they are not only granted the same privileges, but the system will consider them as being the same group. This defeats the purpose of using groups to segregate user privileges.
Security standards forbid sharing a GID among groups. If two groups need to have the same privileges, they should have the same users.
Delete the duplicate groups or assign one of the duplicates a new unique GID.
description: "(arbitrary user comment)"