Keeping Documentation Narrow

Lukas Eder advises against expansive feature cross-pollination in documentation:

Every product manager knows this situation:

• A user works with feature X1.
• They find a limitation / bug / quirk and want to work around it.
• The perfect workaround or alternative is feature X2, but without knowing that X2 exists, the user doesn’t find it and spends a lot of time looking for it.
• The user requests X2 be documented on X1, because that would have saved them a ton of time.

This is such a common pattern, and while it’s perfectly understandable for such a user to request this, it is so terribly wrong to give in to this user’s request. Why is it wrong?

Read on for the answer.