This proposal has been rejected. This decision was taken by the language committee in accordance with the Language proposal policy based on the discussion on this page.
The closing committee member provided the following comment:
Does not have an ISO 639 code. Jon Harald Søby 01:36, 17 February 2008 (UTC)
This language or dialect is spoken in Italy, Tuscany.
Exists wikipedia siciliana, napulitana, sardu, corsu, emiglian e rumagnol...
The wikipedia toscana cans exists too.
more in article Tuscan Dialect.