Excerpt from the linked content^1 by Melissa Heikkilä:

>The popular AI image generator Midjourney bans a wide range of words about the human reproductive system from being used as prompts, MIT Technology Review has discovered.

>If someone types “placenta,” “fallopian tubes,” “mammary glands,” “sperm,” “uterine,” “urethra,” “cervix,” “hymen,” or “vulva” into Midjourney, the system flags the word as a banned prompt and doesn’t let it be used.

>Sometimes, users who tried one of these prompts are blocked for a limited time for trying to generate banned content. Other words relating to human biology, such as “liver” and “kidney,” are allowed.

>Midjourney’s founder, David Holz, says it’s banning these words as a stopgap measure to prevent people from generating shocking or gory content while the company “improves things on the AI side.” Holz says moderators watch how words are being used and what kinds of images are being generated, and adjust the bans periodically.

>The firm has a community guidelines page that lists the type of content it blocks in this way, including sexual imagery, gore, and even the 🍑 emoji, which is often used as a symbol for the buttocks.

>Some terms relating to the male reproductive system, such as “sperm” and “testicles,” are blocked too, but the list of banned words seems to skew predominantly female.

>The prompt ban was first spotted by Julia Rockwell, a clinical data analyst at Datafy Clinical, and her friend Madeline Keenen, a cell biologist at the University of North Carolina at Chapel Hill.

^1 Melissa Heikkilä, MIT Technology Review, 24 Feb. 2023, https://www.technologyreview.com/2023/02/24/1069093/ai-image-generator-midjourney-blocks-porn-by-banning-words-about-the-human-reproductive-system/