Search

Due to the very active R user community (without which R would not be what it is today) there are many possibilities to search in R web pages and mail archives, some of which are listed below:

search.r-project.org
Rseek is provided by Sasha Goodman at Stanford university. This engine lets you search several R-related sites and can easily be added to the toolbar of popular browsers.
r-universe.dev

Thanks to all of them!

In addition, you can always use the advanced search feature of the Google search engine: