As do the cars, drivers who participate in the 24 Hours of Le Mans are classified in four classes according to their age and career record. As these factors change over time, the categorisation can be adjusted each year in accordance with results.
The series using the driver categorisation, like the FIA World Endurance Championship (WEC) of which the 24 Hours of Le Mans is a part, must share the 10 fastest laps of each driver, as well as the race results and qualifying sessions of each race. Of course, any factors that could affect the performances, like weather conditions and race incidents, are taken into account.
A driver looking to participate in one of the series must send a categorisation request to the FIA or won't be allowed to take part in any competition. If (s)he is unsatisfied with the response, (s)he can submit a request for a revision backed up by all the necessary documents for the review of his case and must follow the procedure put in place by the FIA.
"Platinum" drivers are by definition professional drivers who satisfy at least to two criteria listed by the FIA like, for example, having won the 24 Hours of Le Mans in LM P1 or in LM GTE Pro or being a factory driver with results to match.
"Gold" drivers can be professional or amateur drivers if they satisfy to at least one of a list of less demanding criteria than the "Platinum" drivers. A driver who satisfies only one criterion for "Platinum" drivers is automatically considered "Gold."
The "Silver" and "Bronze" classes are only for amateur drivers who must satisfy one criterion to be considered for the first classification, the second reserved for debuting drivers or for those whom have not yet achieved significant results or drivers over the age of 60 no matter their record.
Indeed, age is taken into account. Any driver under the age of 30 is considered at least "Silver" unless (s)he is debuting. Also, the classification of drivers over the age of 50 goes down one grade, whereas that of drivers over 55 goes down two grades.
With the exception of the LM GTE Pro class, in which the composition of the crew is free, each class carries its own rules. In LM P1 - the fastest cars - "Bronze" drivers are not allowed.
In the LM P2 and LM GTE Am classes, in which can be found most gentlemen-drivers, logically a crew of 3 shall not be made up of professional drivers only. In LM P2, a three-driver driver line-up must include a minimum of one "Silver" or "Bronze" driver, whereas in LM GTE Am, a trio must have at least one "Bronze" and one "Bronze" or "Silver" driver.