# PDF vs PMC

> English confusable word pair

## The two words

### PDF
*name · IPA /pi di ɛf/ · frequency rank #9,079*
Initialism of Parkinson's Disease Foundation, now just Parkinson's Foundation.

### PMC
*noun · frequency rank #47,266*
Initialism of private military company or corporation.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-09-03.
Canonical page: https://plainspell.com/en/vs/pdf-vs-pmc