Dimensions has an inclusive approach to publication indexing. We index all source titles covered by our publication data sources such as Crossref or PubMed if they include publications of the supported publication types.
Some users like to overlap their search results with one or more "journal list" filters that limit results only to publications that have been indexed by that particular external journal list - such as PubMed, ERA, or the Norwegian Register - so that they can be sure to only include publications which have met the indexing criteria for those collections. The Journal List filter is available as a filter in all Dimensions versions.
Journals which approach Dimensions/Digital Science for indexing of their publications are checked to ensure that they have not been identified as predatory publishers.