The # prefix for Claude's memory feature has been deprecated in favor of a more transparent CLAUDE.md file approach. Previously, developers used # commands like '# Use bun instead of npm' to create persistent preferences, but this hidden complexity caused confusion about where settings were saved. The new method allows direct conversation with Claude to update preferences or manual editing of the CLAUDE.md file.

This evolution provides better visibility, version control integration, and team collaboration. Developers can now create detailed, structured preference files that commit to repositories, ensuring consistent AI assistance across all team members. The change represents Claude Code's maturation from magic shortcuts to controllable, transparent customization tools that integrate seamlessly with existing development workflows.