sensible-browser (1) - Linux Man Pages
sensible-browser: sensible editing, paging, and web browsing
sensible-editor, sensible-pager, sensible-browser - sensible editing, paging, and web browsing
DESCRIPTIONsensible-editor, sensible-pager and sensible-browser make sensible decisions on which editor, pager, and web browser to call, respectively. Programs in Debian can use these scripts as their default editor, pager, or web browser or emulate their behavior.
STANDARDDocumentation of behavior of sensible-utils under a debian system is available under section 11.4 of debian-policy usually installed under /usr/share/doc/debian-policy (you might need to install debian-policy)