Early experience from creating pipe_base documentation has shown that we need a user documentation content style guide to help us effectively produce consistent and high-quality documentation for end-users.

This style guide becomes a place to:

• Discuss tone and voice for specific types of end-user documentation and share technical writing advice.
• List preferred spellings, especially for domain-specific words. For example, "subtask" or "sub-task" — I've seen both in existing documentation. We need to decide on one. We also need a place to remind use that it's spelled "GitHub."
• Discuss grammar and style issues beyond what is already in the Project Publications Style Manual.

The intent of the user documentation style guide is to respectfully build upon the Project Publications Style Manual. The DM user documentation style guide's default stance should be to inherit the recommendations of the Project style guide. In rare occasions, we may need to override its advice to adopt best practices specific to end-user documentation writing. It's possible that the DM user documentation style guide's recommendations could eventually get moved to Project Publications Style Manual, but I think we will always need a style guide specifically for user documentation because of the unique requirements of user documentation compared to management documentation and scientific articles.

This ticket will seed the user documentation content style guide as a sub-section of the DM Developer Guide.