53 conduct and its distinctive elements, so as to distinguish that conduct from non-punishable behaviors.263 The Court has held that vague or ambiguous provisions that give broad discretionary powers to the authorities are incompatible with the American Convention because they can be used as the basis for potentially arbitrary acts.264 173. The greater the restriction on a human right, the more precise and clear the provisions establishing that restriction must be.265 Thus, the limitations imposed under criminal law are subjected to the strictest test of legality, and must therefore comply with the requirements established in Article 9 of the Convention,266 under which “[n]o one shall be convicted of any act or omission that did not constitute a criminal offense, under the applicable law, at the time it was committed.” The same is true with the restrictions imposed via administrative disciplinary proceedings, particularly when they can lead to serious disciplinary measures such as dismissal. The Inter-American Court has written that Article 9 applies to such proceedings since, like criminal penalties, administrative disciplinary measures are an expression of the State’s punitive authority and can seriously harm or alter a person’s rights or deprive said person of his or her rights.267 174. The foregoing presupposes that the laws establishing administrative sanctions like dismissal must be subjected to the strictest test for legality. Such norms have severe consequences and restrict the exercise of rights; but because they represent an exception to the principle of judicial stability, they can compromise the principles of judicial independence and autonomy. In the specific case of disciplinary proceedings, the Commission has underscored the fact that there must be “clear rules on the grounds and procedure for removing judges from office;”268 “[i]n addition to fueling doubts about the independence of the judiciary,” the absence of such rules “can lead to arbitrary abuses of power, with direct repercussions for the rights of due process and of freedom from ex post facto laws.”269 175. Given the importance of the principle of freedom from ex post facto laws in proceedings in which a judge can be removed from his or her post, international law has set certain requirements that disciplinary proceedings must meet. The law must give detailed guidance on the infractions by judges that trigger disciplinary measures, including the gravity of the infraction, which in turn determines the kind of disciplinary measure to be applied in the case at hand.270 In Maestri v. Italy, the 263 Cf. I/A Court H.R., Case of Usón Ramírez v. Venezuela. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 20, 2009. Series C No. 207, paragraph 55, and Cf. Case of Baena Ricardo et al. v. Panama. Merits, Reparations and Costs. Judgment of February 2, 2001. Series C No. 72, paragraphs 105-107. 264 See, IACHR, Report of the Office of the Special Rapporteur for Freedom of Expression 2009, OEA/Ser.L/V/II.Doc. 51, December 30, 2009, Chapter III, paragraph 70. 265 Cf. I/A Court H.R. Case of Kimel v. Argentina. Judgment of May 2, 2008. Series C No. 177, paragraphs 59 et seq 266 Cf. I/A Court H.R. Case of Baena Ricardo et al. v. Panama. Merits, Reparations and Costs. Judgment of February 2, 2001. Series C No. 72, paragraphs 105-108. 267 Cf. I/A Court H.R. Case of Baena Ricardo et al. v. Panama. Merits, Reparations and Costs. Judgment of February 2, 2001. Series C No. 72, paragraphs 106 and 108. 268 IACHR, Case 12,600, Hugo Quintana Coello et al. (Supreme Court) with respect to Ecuador (Merits), August 2, 2011, paragraph 95. 269 IACHR, Case 12,600, Hugo Quintana Coello et al. (Supreme Court) with respect to Ecuador (Merits), August 2, 2011, paragraph 95. 270 United Nations. General Assembly. Human Rights Council. Report of the Special Rapporteur on the independence of judges and lawyers, Leandro Despouy, A/HRC/11/41, March 24, 2009, paragraph 57. Also, the Universal Charter of the Judge