{"source":"semconv","version":"1.44.0","attribute":{"id":"url.subdomain","type":"string","stability":"development","brief":"The subdomain portion of a fully qualified domain name includes all of the names except the hostname under the registered_domain. In a partially qualified domain, or if the qualification level of the full name cannot be determined, subdomain contains all of the names below the registered domain.","note":"The subdomain portion of `www.east.mydomain.co.uk` is `east`. If the domain has multiple levels of subdomain, such as `sub2.sub1.example.com`, the subdomain field should contain `sub2.sub1`, with no trailing period.","examples":["east","sub2.sub1"],"namespace":"url","definedIn":"model/url/registry.yaml","usedBy":[]},"history":[{"version":"1.30.0","publishedAt":"2025-01-24T19:11:42Z","kind":"first-seen","detail":"Already present at v1.30.0, the oldest release tracked here (experimental)."},{"version":"1.31.0","publishedAt":"2025-03-11T00:53:13Z","kind":"stability-changed","detail":"Stability label respelled from experimental to development.","severity":"informational"}],"replaces":[]}