ANATEL has, recently, updated its way to publish the regulations established by them for Certification and Homologation Processes. Since technology exponentially evolves, ANATEL has changed their internal procedure, to be able to make faster changes, in order to keep up with the technology evolution. Now, instead of Resolutions (E.g: Resolution 442, Resolution 506, Resolution 529, etc.) ANATEL is publishing its regulations in form of “ATOs”. The reason for this change is that the procedure to update technical parameters in ATOs is easier, faster, and less bureaucratic than the procedure to update the same parameters in Resolutions.
You can find a file informing which ATO corresponds to which Resolution at https://goo.gl/ZuLzdk.