sameAs Property.

A company exists online in many places: its own website, LinkedIn, Google Business Profile, the commercial register, trade directories, professional profiles. To a person it is obvious that all of this refers to the same firm. To a machine it is initially a collection of unconnected URLs. The sameAs property solves that by listing explicitly, in the JSON-LD of your own site, which further addresses describe the same entity. Scattered occurrences become a single, evidenced profile. The markup runs to a few lines and has one of the best effort-to-effect ratios available.

Technically, sameAs is an array of URLs inside an Organization, LocalBusiness or Person object. Only addresses that are genuinely under your control or officially issued belong there: company profiles on social networks, Wikidata or Wikipedia entries, commercial register and trade association profiles, verified directory listings. Third-party mentions, press articles or pages where the company merely appears do not. sameAs asserts identity, not relatedness, and a wrong entry weakens the whole markup. A short, well-kept list therefore beats a long one padded with partner sites and unverified directories.

The benefit lies in entity resolution. When a search engine or a language model has to decide whether 'Muster Digital' on three different pages refers to the same firm, sameAs supplies the evidence. That matters especially when the company name is not distinctive, or when a rename has taken place. A Wikidata entry carries disproportionate weight here, because many systems use Wikidata as their reference source for entities. The property is no substitute for consistency, though: it links what already exists and corrects no contradictory data.

An example from practice: after a rename, a business ran the old and the new name in parallel across various directories. Assistants described the two as separate providers, sometimes with different details. The way out was to carry the new name as 'name' and the old one as 'alternateName' in the site's JSON-LD, link every official profile through sameAs, and clean up the directory entries that still carried the old wording. After that the two profiles collapsed back into a single entity.