3. Levels of Abuse - Invalid and IllicitBefore getting into the specific abuses, it is important to understand the rules for celebrating the Holy Sacrifice of the Mass. These rules are officially called rubrics. These rubrics are contained in the General Instruction of the Roman Missal (GIRM)[1], and many clarifications have been made in more recent documents such as Instruction Concerning Worship of the Eucharistic Mystery (Inaestimabile Donum). The most serious type of abuse makes the Mass "invalid." For a Mass to be invalid, the Consecration of the Eucharist does not occur. Going to an invalid Mass is like not...