Authors who care about comprehension usually qualify abbreviations the first time they use them. So what's a PPA? OK, this is a technical site where explanation may be considered otiose. But I'm enough of a technician to earn a good living at it, I'm also a regular Linux Mint user, and I haven't a clue what a PPA is. Perhaps I haven't been paying attention.
Google is your friend, of course. But would it have cost anything to indicate which of the 2,520,000 PPA results is meant? Is it Professional Publishers Association, Prescription Pricing Division, Performance Preparation Academy, Personal Package Archive, Power purchase agreement, The Play Providers Association, PPA Awards, The Chartered Society of Physiotherapy, or one of the other 2,519,992?