Optional listing venue to pin the response to a specific exchange. Accepts the venue's ISO 10383 MIC (XWBO for the Wiener Börse, XNAS for NASDAQ) as well as our own short code for the same venue (VIE, NASDAQ, MUN); both spellings resolve to the same listings. Segment MICs are not resolved yet — for a venue whose segments carry their own MIC (the Wiener Börse's WBAH, WBGF, WBDM), pin the operating MIC XWBO or the short code VIE. Honored for isin AND symbol requests. When omitted, the listing named by the symbol answers (our symbols are RICs: EBS.VI is the Vienna listing, EBO.DE the XETRA one); for an isin request, or for a named listing that has no data in the requested window, the security's canonical listing answers. Where the response has an exchange field, it always names the venue that actually answered. A venue the instrument is not listed on is never silently replaced by another listing — /v2/timeseries/candles and /v2/timeseries/history reject it with 400 and name the venues the instrument does have, while /v2/timeseries/eod and /v2/timeseries/quote return no data.