Denominao de Origem Controlada is a top level wine classification  with internationally recognizable identities for their wines.
In addition to the top-level DOC designation, there are two secondary tiers: Indicacao de Proveniencia Regulamentada (IPR) and Vinho Regional. IPRs are similar to DOC "in training" and indicate regions that have established their own regulating bodies but have not yet established an internationally recognizable identity for their wines. 
