KERML_ — Some package-level features are mandatory

[From Vince Molnar] Package-level features do not give featuring types, and some have lower multiplicity greater than zero, meaning everything in the universe (instances of Anything), including every data value, is required to give at least that number of values to them (see KERML-56). For example, the libraries include:

Clocks::universalClock[1] {...}
Observation::defaultMonitor[1] : ChangeMonitor[1] {...}
SpatialFrames::defaultFrame : SpatialFrame[1] {...}

Might be others. This one

Occurrences::earlierFirstIncomingTransferSort: IncomingTransferSort{... }

does not give a multiplicity, I couldn't find what this means (even for expressions), tho this particular feature is supposed to have exactly one value.