> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prompts.ag/llms.txt
> Use this file to discover all available pages before exploring further.

# Markdown in XML tags

> Frontier models converge on the same format: Markdown content wrapped in XML-like tags.

Frontier models converge on the same format: Markdown content wrapped in XML-like tags. Here's what they want:

## Use XML-like tags for structure

Wrap distinct sections of your prompt in descriptive tags. Tags create clear boundaries that help models parse complex prompts reliably.

## Choose descriptive tag names

There are no canonical "best" tag names. Use names that describe the content: `<context>`, `<instructions>`, `<example>`, `<data>`. Be consistent within a prompt.

## Keep Markdown inside tags

Content within tags can use full Markdown formatting—lists, headers, code blocks. The tags provide semantic structure; Markdown handles formatting.

## Nest tags when needed

For hierarchical content, nest tags naturally. A `<examples>` section might contain multiple `<example>` tags. Maintain consistent indentation for readability.

## Attributes: labs differ

Anthropic recommends no attributes—use nested tags for metadata. OpenAI supports attributes like `<doc id="1" title="...">`. For portability across models, avoid attributes or test both approaches.

## Long context: repeat instructions

For prompts with extensive context, place instructions at both the beginning and end. This helps models maintain focus on your requirements throughout processing.

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**Sources:** [Anthropic](https://docs.anthropic.com/en/docs/build-with-claude/prompt-engineering/use-xml-tags) · [OpenAI](https://developers.openai.com/cookbook/examples/gpt-5/gpt-5-2_prompting_guide/) · [Google](https://cloud.google.com/vertex-ai/generative-ai/docs/learn/prompts/structure-prompts)