Walter is seeing `?hsCtaTracking=...` appended to the URL of their website (which is not hosted on HubSpot) and wants to know why it appears and how to remove it.

Anton explains that the `hsCtaTracking` query parameter is automatically added by HubSpot when a visitor clicks on a HubSpot Call-to-Action (CTA) button or link that directs them to that URL. It's used purely for tracking the performance of that specific CTA within HubSpot analytics.