Output Format

I have to state format requirements in every prompt — is there a way to have Claude remember my format preferences?

Yes — this is one of the core uses of Claude Projects' Custom Instructions.

Approach: write your most commonly used format preferences into your Project's Custom Instructions. For example: 'Unless I specify otherwise, all outputs should follow these format guidelines: tone like colleague-to-colleague communication (not too formal, not too casual); each response under 300 words; if information can be bulleted, prefer bullets over paragraphs; don't add closing pleasantries like "if you have any questions, feel free to ask" at the end of responses.'

After setting this up, every conversation in this Project automatically outputs according to these format preferences without you re-stating them. You only need to specify in conversation when you have special needs (more formal this time, longer this time), and Claude will prioritize your real-time request.

When should I use bullet points, and when paragraphs? I'm often unsure which is better.

A judgment principle: is there a logical parallel relationship between pieces of information?

Suited for bullets: information is parallel and independent (e.g., 5 cautions, 3 steps, 4 options); the reader needs to quickly scan for specific items; output will be pasted in a chat tool or presentation needing visual clarity.

Suited for paragraphs: information is sequential with causal relationships (argument and evidence, analysis and inference); the output's purpose is to persuade or build complete understanding, not just list facts; output will be in formal documents or emails where paragraphs are more reading-appropriate.

Common mistake: force-bulleting what should be an analytical paragraph, losing the logical connections between points. Better approach: use paragraphs when there's logical flow; use bullets when it's truly just a parallel list.

Most direct way to tell Claude: 'This output needs readers to quickly scan for key points — please use bullets' or 'This output needs readers to build complete understanding — please use paragraphs.'

Are there situations where I specify format requirements but Claude still doesn't follow them? Why?

Yes — usually two causes:

First, format requirements conflict with the nature of the task. For example, you say 'answer in three bullet points' but the question fundamentally requires continuous logical reasoning. Force-compressing to three points may lose important context. Claude sometimes prioritizes 'giving you a correct answer' over 'giving you a format-compliant answer' — this is actually its attempt to be responsible to you, but may feel like not following instructions.

Second, format requirements aren't specific enough. 'Please be brief' is vague to Claude — what does brief mean? 50 words? 200 words? If format requirements aren't precise, Claude interprets according to its own judgment. Solution: use specific numbers or examples rather than abstract adjectives.

If you specified format requirements but Claude didn't follow them, the most effective approach is to directly point it out: 'The last response was too long — I said under 150 words. Please regenerate a version that meets this word limit.'

How do I design corresponding format instructions for different downstream uses (Slack message vs. email vs. presentation vs. document)?

Different downstream uses have very different format requirements. Format instruction recommendations for common scenarios:

Slack / instant messaging: 'Please write in Slack message format — no more than 3 paragraphs, 2-3 lines each, tone like a colleague conversation, no formal opening or closing needed.'

Email: 'Please write as a business email — with an opening (salutation), body (2-3 paragraphs each focused on one point), closing (next steps or call to action). Tone professional but not overly formal, avoid excessive business jargon.'

Presentation slide notes: 'Please write the key talking points for this slide — use 3-4 bullets, each under 15 words, conversational tone, as prompts for what I'll say verbally, not complete paragraphs.'

Formal document: 'Please write this section in formal document format — complete sentences and paragraphs, objective and professional tone, avoid first person.'

These format instructions can be stored as part of Custom Instructions or added directly to prompts when needed.