What is the PRC format?

PRC — Mobipocket eBook (PRC)

PRC is a Mobipocket e-book under the Palm resource extension, the same format as MOBI, common in old e-book collections and early Kindle books.

R convert from PRC PRC Converter

Convert PRC to

Mobipocket books were often distributed as .prc files for Palm devices. They read like MOBI files on Kindles and in Calibre.

Most current reading apps prefer EPUB. Converting PRC to EPUB or AZW3 keeps old books readable.