The Custom Dictionary helps correct recurring spelling mistakes in names, brands and specialist vocabulary. The current Help Center documents a dictionary editor on Windows.
A rule such as cubernetes → Kubernetes is useful when that is a recurring error. A broad rule for a common word can change text that was already correct.
A replacement dictionary adjusts recognised text. It does not mean the underlying speech model has been retrained on your voice. Check each result, especially when a term can have several meanings.
The desktop editor does not establish that dictionary import or selection-based additions are already available everywhere. Check your build’s settings and the roadmap for those workflows.
The planned Learning System is intended to make corrections easier to collect. It is described separately as a feature in development.
More platform-specific guidance: VoicePad Help Center.