the fourteen kinds, and the notation a class diagram is made of
Built as a memo rather than a table: the thing worth hanging it up for reads across the room, with the full reference in smaller type below it.
Three sizes in one archive — from a sheet on the fridge to a poster on the wall.
The notation, the division into fourteen kinds and every clause reference are from OMG UML 2.5.1 (formal/2017-12-05). A miniature shows the characteristic symbol of a kind, not a complete diagram.
The filled diamond, composition, is defined exactly: the composite is responsible for the existence and storage of its parts, a part belongs to at most one composite at a time, and the parts are deleted along with the whole.
The hollow diamond, shared aggregation, is not defined at all. In the words of the specification, the precise semantics of shared aggregation “varies by application area and modeler”. A hollow diamond therefore tells the reader nothing that a plain association line would not, and its meaning has to be agreed afresh every time.
The same holds for multiplicity, and this one applies to every diagram: if no multiplicity is shown on an association end, no conclusion may be drawn about the multiplicity in the model. Not one, not many — unknown.
Why the numbers can be trusted. Every countable number here is computed from data rather than typed in, and the sheet must pass 8 independent checks before it is allowed to build — how many items there are, the order they come in, and the claim in the highlighted box itself. If one fails, there is no file.
ten tasks, the year of each, the system, the figure — and the human it was measured against
who published each standard, when, what it does to the sound, and how many bits per second it allows
two scales · 1000 and 1024 · why a drive looks smaller
main axis and cross axis · which property belongs to which