In legitimate programming and user-experience circles, "CP" often stands for specific open-source software, scripts, or content aggregators designed for imageboards.
Over the years, 4chan has faced criticism and legal pressure regarding CP content. The site's administrators and users have implemented various measures to combat the issue: cp 4chan updated
Here's an essay on the topic:
The strict refinement of 4chan's safety policies fundamentally reshaped the dark underbelly of the web. As 4chan’s developer tools and moderation squads grew increasingly aggressive in purging illicit content, bad actors experienced total displacement from the site. In legitimate programming and user-experience circles