Classifications are more likely to be conventional than descriptive. So they are also more or less useful.
A desirable feature of classification is exhaustivity but is easily obtained by including a class "Other". Thus a most rudimentary form is a series of descriptions ('bullets'), with the last one labelled 'other'.
Logic also achieves exhaustion if a feature, that is a predicate, applicable to the whole domain is chosen: anything is either an "A" or a "not-A". If two such independent features are known, on may obtain a complete fourfold classification (e.g. 11, 10, 01, 00).
The four suggested purposes are actually two pairs that are not well separated as they are based on something like ego vs. not-ego and plan vs. no-plan, both being roughly along the axis inside vs outside.