programmatic-label.md

title	Programmatic Label
key	programmatic-label
unambiguous	true
objective	true
input_aspects	DOM tree

Element L is a programmatic label of target element T if either:

• T is a labeled control of L; or
• L is referenced by ID in the aria-labelledby attribute of T.

For more details, see examples of programmatic label.

Note: a given element may have more than one programmatic label.

The labeled control L of an element T is its explicit label if L has a for attribute referencing T's id attribute.

The labeled control L of an element T is its implicit label if L has a no for attribute and is an ancestor of T in the DOM tree. Note that explicit labels take precedence over implicit label, and that [labeled controls][labelled control] do not cross shadow boundaries nor content documents.