In the Philippines, senior citizens are entitled to a 20% discount on jeepney fares under the Expanded Senior Citizens Act (RA 9994). To avail of this discount, seniors should present a valid Senior Citizen ID to the driver or conductor. It's important to note that the discount applies only to the fare and not to other charges like terminal fees. Each jeepney operator may have their own implementation protocols, so it's a good idea to check with local transport authorities or the jeepney operators for any specific rules or guidelines.