Custom expander (ARIA Disclosure Widget)

On focus, the expander <button> must identify its name, role and state.

The (International) Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear code words for communicating the letters of the Roman alphabet.

Native expander

On focus, the details/summary element must identify its name, role and state.

About the NATO alphabet

The (International) Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear code words for communicating the letters of the Roman alphabet.