.TP
.B Ctrl\-o
show the sourcecode of the current page.
+.SH ENVIRONMENT
+.TP
+.B SURF_USERAGENT
+If this variable is set upon startup, surf will use it as the useragent string
+.TP
+.B http_proxy
+If this variable is set and not empty upon startup, surf will use it as the http proxy
.SH SEE ALSO
.BR dmenu(1),
.BR xprop(1),