293. Practically all legal systems establish as a requirement that EDRB members must be a citizen in the full exercise of their rights, with a minimum age limit ranging from 30 to 45 years. Some provide a maximum age of 70 or 75 years. In any event, equal opportunity to access the position of a member of an EDRB should be guaranteed, avoiding any vestige of discrimination and taking account of the desirability of inclusion, particularly of gender and ethnic minorities. 294. Given the impartiality with which the various types of electoral challenge must be resolved, the requirements not to have recently held any position in a political party, not to hold one while a member of the EDRB and not to support any candidate are especially important. Other explicit requirements are honesty and probity or a good reputation, and a large number of EDRBs require that members should not have been convicted of any criminal offence, or of one that entailed imprisonment. 295. In addition, some legal systems establish as a requirement for membership of an EDRB that a person must not hold certain public positions, or that having held an electoral position is a temporary disqualification from holding certain public positions in the future. In the vast majority of cases, this is a ‘good practice’ for safeguarding impartiality. Similarly, some systems require that members must not be members of the military, whereas others require that they do not have family members in the EDRB or even family members in certain public offices or who sit as legislators. Along these lines, it is good practice for members not to have any business dealings with the executive and not to hold any government concession or contract. iv) Security of position and career service 296. To ensure that those sitting in judgement on electoral matters remain independent while they perform their functions, legislation often provides for various measures aimed at insulating members from any pressures by means of sanctions, reprisals or even apparent rewards from those who obtain judicial judgements contrary to or coinciding with their interests. Such safeguards include security of tenure. 297. The law generally establishes a predetermined term of office for judicial positions which cannot be reduced or prolonged except by provision of law. This consolidates the independence of those who judge electoral matters: they cannot be dismissed or removed for having handed down decisions that do not please, or are considered inconvenient by certain political parties or individuals. They can only be removed on the basis of the specific grounds set out in the constitution and the law. 298. The security of judges in their posts is considered to be one of the most important structural guarantees. The strongest guarantees for EDRB members 106