A scholarly index is a curated list of publications — usually journals, sometimes conferences or books — that a given service has decided to cover, together with the records it holds for them. Indexing matters because it determines visibility, and in some systems eligibility for metrics. Each index publishes its own selection criteria and applies them itself, so inclusion in one says nothing about inclusion in another, and the phrase “indexed journal” without a named index carries no information at all. The category is defined by no external body; what exists is a set of competing services, each documenting its own boundaries, alongside a persistent problem of predatory outlets claiming indexing they do not have. Citing one operator’s criteria page would make its policy look like a general standard.
Why this entry carries no source list. This lexicon cites an official primary source wherever one exists, and says so plainly where none does. No body governs this term. There is no standards organisation for it, no register, and no text whose authors could claim to have settled its meaning. Methods literature describes practice and argues about it; a citation to one author would dress a position in a live argument as a rule, which would mislead more than silence does. What follows is the convention as it is actually used, with the disagreements named rather than smoothed over.