The purpose of this guide is to present to the reader, in an objective way, the changes in spelling of the Portuguese language due to the Portuguese Language Orthographic Agreement, signed in Lisbon on December 16, 1990 by Portugal, Brazil, Angola, São Tomé and Príncipe, Cape Verde, Guinea-Bissau, Mozambique and later for East Timor. In Brazil, the Agreement was approved by the Legislative Decree No. 54 of April 18, 1995.
This guide has been prepared in accordance with the 5th edition of the "Vocabulário Ortográfico da Língua Portuguesa" (VOLP), published by the Brazilian Academy of Letters in March 2009.