My format for 'Now Playing Simple' foobar2000 plugin.

foo_np_simple-no_indicator.txt

$if(
%isplaying%,
$if(%ispaused%,Ⅱ,▶)
$if(%album%, %album%$crlf() )
$if(%artist%, %artist%$crlf() )
$if(%title%, %title% , %filename%)
)

foo_np_simple-single_letter_progress_indicator.txt

$if(
%isplaying%,
$if(
%ispaused%,
Ⅱ,
$puts(remaining,%playback_time_remaining_seconds%)
$puts(length,%length_seconds%)
$puts(eighth,$div($get(length),8))
$select(
$add(
1,
$ifgreater($get(remaining), $mul($get(eighth),1),1,0),
$ifgreater($get(remaining), $mul($get(eighth),2),1,0),
$ifgreater($get(remaining), $mul($get(eighth),3),1,0),
$ifgreater($get(remaining), $mul($get(eighth),4),1,0),
$ifgreater($get(remaining), $mul($get(eighth),5),1,0),
$ifgreater($get(remaining), $mul($get(eighth),6),1,0),
$ifgreater($get(remaining), $mul($get(eighth),7),1,0)
),
█,▛,▜,▀,▙,▌,▚,▘
)
)
$if(%album%, %album%$crlf() )
$if(%artist%, %artist%$crlf() )
$if(%title%, %title% , %filename%)
)