[Iverilog-devel] What file suffix is usually used for the filename following a -o?

[Kevin S. <kvn...@ho...>]

When I try to execute the Icarus tool on a System Verilog file I execute something like this:
\Icarus\bin\iverilog -g2009 -o example.(file-suffix) example.sv
What do people typically use for (file-suffix)?