One parameter of a function/method, or one attribute of a custom element -- whatever the language, a name, a type, an optional default and a description.
class MMO\doc\models\DocParam extends MMO\doc\models\DocNode
Read a key, without the "undefined array key" notice $node['missing'] would raise (tArray::offsetGet returns by reference, so it cannot null-coalesce on its own).
\ArrayAccess::offsetUnset -- on a list (sequential integer keys, as produced by $bag[] = ...), the element is spliced out (closing the gap and reindexing), matching \unset() semantics on a plain …