---
layout: rule
id: GORULE:0000055
title: "References should have only one ID per ID space"
type: report
fail_mode: soft
status: implemented
contact: "go-quality@lists.stanford.edu"
---
Since references should only refer to single publications, multiple IDs indicate
alternate IDs for the same publication. So different reference IDs should be in
different ID spaces. More than one ID in the same space implies distinct publications
are being referenced, which is not allowed.