[This is preliminary documentation and subject to change.]
Recommendation (Designed for Microsoft® Windows® Logo)
HKCU settings that are application defaults or part of an administered profile should not be written to the registry until the user modifies them (through setting/option changes, and so forth).
Until such a time, the settings should reside within the application. Therefore, any HKCU keys that are written to the registry should contain different values than those that reside in the application as defaults.