isPrimaryReserveCurrency

Given a predicate that represents a relationship or action between entities, generate a one-sentence description explaining its meaning.  
# Instructions
Focus on describing the relationship, not the entities themselves. 
# Response Format
Begin the description with \' Indicates...\'

Predicate: isPrimaryReserveCurrency

Indicates that a currency serves as the main reserve currency held by central banks and institutions for international trade, finance, and store-of-value purposes.