The concept is flawed, and mostly useless. Let's finally remove it. It has been deprecated since 90a2ec10f2d43a8530aae856013518eb567c4039 (6 years ago) and we started to warn since 55dadc5c57ef1379dbc984938d124508a454be55 (1.5 years ago). Let's get rid of it altogether.
System and Service Manager
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