The 20% senior discount in the Philippines applies to various goods and services, including food, medicine, transportation, and utilities. To avail of this discount, seniors need to present a valid senior citizen ID at the point of purchase or service. It's important to note that the discount is not automatically applied; it must be requested by the senior. Also, for specific eligibility and coverage details, it's advisable to check with the official government website or consult local businesses, as practices may vary.