O que significa isso?
t=canonical
is a partner tag that allows Ubuntu to generate revenue from searches on DuckDuckGo that use Ubuntu (anonymously)
Fonte DuckDuckGo no Twitter
&t=
Through partnerships 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.
Fonte & t =
&ia=web
- o ia
é a abreviação de "acesso instantâneo", mas não consigo encontrar uma boa referência da web que descreva esse parâmetro.