# What is the ‘t’ URL parameter for on DuckDuckGo Search?

Through [partnerships](/content/duckduckgo-help-pages/company/partnerships/index.html) with developers and companies, DuckDuckGo has been integrated into many applications. In these partnerships, a portion of DuckDuckGo's advertising revenue is sometimes shared back. To assign advertising revenue and collect anonymous aggregate usage information, developers add a unique "&t=" parameter to searches made through their applications.