Oh well, guess i get to make up my own unofficial letters. Thanks.

What makes a fricative sibilant? What’s the difference between sibilant and non-sibilant fricatives?

In case people misunderstand the title and start asking and answering small questions here, my question is does the IPA have a way of writing sounds made with the tongue rolled (not a trill)? For instance, sticking my tongue out rolled and making a voiced fricative that way gets me what sounds like a cross between /ð/ and /β/, and trying to say /a(sound)a/ comes out as [aw(sound)a].