ISSN records are enriched by information extracted from indexing and abstracting databases, directories (DOAJ, Latindex, The Keepers registry) and journals indicators (Scopus). [See the list of Data Sources: https://portal.issn.org/node/91]

ISSN numbers are used as a matching key linking ISSN records with metadata related to their coverage by abstracting/indexing services or bibliometrics. External data give a quality insight on scholarly resources in ROAD, as the scholarly resources are indexed, evaluated and selected for their compliancy with some criteria set upon metrics, ethics and the preservation programs engaged.

Bibliometrics (impact factors) as well as indexing and abstracting services or external directories are mentioned on ISSN records if the case occurs.