Shoutcastv2 - v1 protocol - Http title update

[DJAnonimo]

Hi,

I'm using a http query method to update now playing title.

code:
...admin.cgi?pass=passwd&mode=updinfo&song=Title

The problem is that I want to remove the title in some situations and also I want to set it to "-".
If I do

code:
&song=-

the server says that is invalid input. Before when I was using Edcast for streamit worked and it was setting the "-" as title.

I tried with URL encoding like

code:
&song=%2D

but no luck. But for example the char is accepted when not alone. For example

code:
&song=-TEST

works.

What do I need to query to get the title empty or "-" ?

Thank You in advance!