Project instructions should contain persistent behavioral requirements that apply across the Project’s recurring tasks. Option B defines the expected structure and length of typical deliverables, while Option C establishes the organization’s brand voice and tonal requirements. Both are stable instructions that Claude should consistently apply across chats.

Option A concerns unrelated internal messages and therefore does not belong in a Project dedicated to external writing deliverables. Option D reflects one reviewer’s personal preference rather than an approved organizational standard. Option E can be valuable, but the representative document itself is better stored as Project knowledge or attached reference material. The custom instructions can direct Claude to follow that approved example, but they should not attempt to reproduce an entire sample document unnecessarily.

Anthropic explains that Project instructions are intended to provide project-specific context, workflow guidelines, task requirements, and roles that apply consistently across multiple conversations. Uploaded Project knowledge supplies the source documents and reference examples Claude should consult. Separating durable behavioral rules from supporting reference material makes the configuration easier to maintain and reduces conflicting guidance. Consequently, B and C are the correct instruction-level elements. Anthropic’s personalization and Project-instruction guidance

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