Coding style: PHPDoc Type: type[] mentioned but not clear.

The docs (https://docs.moodle.org/dev/Coding_style#Types) say:

• When multiple occurrences of a given "type" are used, it's highly recommended to document them as type[] instead of the simpler and less informative "array" alternative.

The definition of "multiple occurrences" is not clear enough, type[] is simply defines an array of elements of given type, (e.g. int[] or stdClass[]). I suggest to rephrase in a way:

When value represented as array of given type, it's highly recommended to document them as type[] instead of the simpler and less informative "array" alternative (e.g. int[] or stdClass[]).

While you are changing that part of wiki anyway, I think it could be useful to add the example of using pipe for multiple types:

• When multiple different types are possible, they must be separated by a vertical bar (pipe) (e.g. @return int|false)