Consistent identification

WCAG success criterion 3.2.4 asks one question of a whole product rather than of a page: components with the same functionality are identified consistently. If the button that commits a record is called Save on one screen, Store on the next and left as an unlabelled icon on the third, every screen teaches the reader a new word for a thing they already know. Its sibling criterion 3.2.3, consistent navigation, says the same about repeated navigation: same order, same names, screen after screen.

The cost is highest for readers who never see the layout. A screen reader user finds controls by name and builds a mental index of them, so three names for one function is three entries to maintain and two chances to conclude that this screen does not have the thing they wanted. It is equally a cognitive load issue: recognition is cheap, recall is not, and inconsistent naming converts one into the other. The fix costs nothing at build time and is nearly impossible to retrofit, which is why it belongs in the vocabulary rather than in a late audit.

Consistency means the accessible name as well as the visible label, and it means the icon too. Two buttons named Save that carry different glyphs are inconsistent to the reader scanning for the shape, and a matching glyph with mismatched names is inconsistent to the reader listening. Identical function is the test, not identical appearance: a Delete in a toolbar and a Delete in a row menu can look different and must still be called Delete. The criterion does not ask for a house style, only for one name per function.

Two neighbours worth separating. Consistent help, criterion 3.2.6, is the same instinct applied to one specific thing: if a help mechanism is on multiple pages, put it in the same relative place. And a control that deliberately renames itself as its state changes, the pattern under morphing controls, is a different question entirely: Follow becoming Following is one function reporting its state, which is fine, while Save becoming Store on another screen is two names for one function, which is the failure. If you are unsure which you have, ask whether the name changed because the state did.