Same as GET without a body (German locale)

Click attribution prefix stored in the recorded click source; defaults to voltplan.

Marketplace override, highest precedence. Accepts a marketplace code (de, us, uk, fr, es, it, au), a country alias (at, ch, lu, nl, se, dk, no → de; be → fr; ca, mx → us; nz → au; ie, gb → uk; pt → es), a language code (en → us, de, fr, es, it) or a lang-COUNTRY tag (country part tried first, then language). Case-insensitive; any other value is ignored and the next region signal applies.

Same as region; read only when region is absent or empty.

Region override header, used when no query override applies.

Read only when x-voltplan-region is absent or empty.

CDN country header; checked after the VoltPlan headers.

CDN country header; checked after x-vercel-ip-country.

CDN country header; checked after cf-ipcountry.

First address is GeoIP-resolved to a country when no header above yields a region.

GeoIP-resolved when x-forwarded-for is absent.

Last signal: the first language range that normalizes to a region wins.