Defining terms, describing scope.
Guidelines for getting initial approval to begin, talking to legal, etc.
Vetting the project idea, making sure it's right for open source, initial scoping, early choices re: language, tools, architecture.
Common challenges of open sourcing after the fact, methods for tackling obstacles.
How to repo, useful abstraction, handling assets.
Choosing the scope, scale, and character of your docs, audience considerations, examples.
Levels of community engagement, building for productive interactions.
Release types and use cases, frequency, communication.
Building to withstand organizational change, how to handle various futures.
Likely a collection of practices mentioned in the doc and abstracted/reiterated here as a reference.