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Apple to Remove 'Master/Slave' and 'Blacklist' Terms From Coding Platforms

The company is telling developers to instead use inclusive language terms such as 'primary/secondary' and 'deny list/allow list' when it comes to documenting and coding their software projects.

 & Michael Kan Principal Reporter

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Apple is joining a movement to remove the racially loaded terms “master/slave" and “blacklist/whitelist” from its coding platforms. 

On Thursday, the company announced it was phasing out the “non-inclusive language” across Apple’s developer ecosystem, including Xcode, a suite of software tools to create apps for the Mac and the iPhone.  

For decades now, the term master/slave has been used in IT terminology to describe one device or process that controls another. However, there’s been a growing push from the programming community to retire the term and replace it with neutral language. 

Apple’s updated style guide now tells developers to substitute the terms with “primary/secondary” or “host/client” in their software programs. If necessary, the master/slave term can still be permitted in the computer coding itself, but the company is calling for developers to use alternative terms in documentation manuals.

In addition, Apple is telling developers to avoid using blacklists/whitelists, another IT technology term that critics say perpetuates racial stereotyping. The company is instead recommending developers use the terms “deny list/allow list” or “unapproved list/approved list.”

an image with the word blacklist

The company began making the changes on June 22 at its virtual Worldwide Developer Conference (WWDC). “Developer APIs with exclusionary terms will be deprecated as we introduce replacements across internal codebases, public APIs, and open source projects, such as WebKit and Swift,” the company added this week.

Other computing platforms, including Python and Github, have also been retiring the old-school IT terminology. Last week, Linux founder Linus Torvalds approved a change in the Linux kernel to remove the master/slave and blacklist/whitelist terms. Intel engineer Dan Williams, who came up with the proposal, explained why the change was important. 

“The African slave trade was a brutal system of human misery deployed at global scale. Some word choice decisions in a modern software project does next to nothing to compensate for that legacy. So why put any effort into something so trivial in comparison? Because the goal is not to repair, or erase the past. The goal is to maximize availability and efficiency of the global developer community to participate in the Linux kernel development process,” he wrote in the Linux kernel mailing list earlier this month. 

Although critics may argue taking out blacklist/whitelist goes too far, according to Williams it’s evident the terms are problematic. “One thought exercise is to consider replacing 'blacklist/whitelist' with 'redlist/greenlist'. Realize that the replacement only makes sense if you have been socialized with the concepts that 'red/green' implies 'stop/go,'” he wrote. “The socialization of 'black/white' to have the connotation of 'impermissible/permissible' does not support inclusion.”

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About Our Expert

Michael Kan

Michael Kan

Principal Reporter

My Experience

I've been a journalist for over 15 years. I got my start as a schools and cities reporter in Kansas City and joined PCMag in 2017, where I cover satellite internet services, cybersecurity, PC hardware, and more. I'm currently based in San Francisco, but previously spent over five years in China, covering the country's technology sector.

Since 2020, I've covered the launch and explosive growth of SpaceX's Starlink satellite internet service, writing 600+ stories on availability and feature launches, but also the regulatory battles over the expansion of satellite constellations, fights with rival providers like AST SpaceMobile and Amazon, and the effort to expand into satellite-based mobile service. I've combed through FCC filings for the latest news and driven to remote corners of California to test Starlink's cellular service.

I also cover cyber threats, from ransomware gangs to the emergence of AI-based malware. In 2024 and 2025, the FTC forced Avast to pay consumers $16.5 million for secretly harvesting and selling their personal information to third-party clients, as revealed in my joint investigation with Motherboard.

I also cover the PC graphics card market. Pandemic-era shortages led me to camp out in front of a Best Buy to get an RTX 3000. I'm now following how the AI-driven memory shortage is impacting the entire consumer electronics market. I'm always eager to learn more, so please jump in the comments with feedback and send me tips.

The Best Tech I've Had:

  • My first video game console: a Nintendo Famicom
  • I loved my Sega Saturn despite PlayStation's popularity.
  • The iPod Video I received as a gift in college
  • Xbox 360 FTW
  • The Galaxy Nexus was the first smartphone I was proud to own.
  • The PC desktop I built in 2013, which still works to this day.

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