Pinyin is only used for pronunciations, a phonetic symbol.
From the economist.com
The exclamation point has sometimes been used as a phonetic symbol to indicate that a consonant is ejective.
From the en.wikipedia.org
Because of this standard, the minuscule letter was chosen to be used in the IPA as the phonetic symbol for the sound.
From the en.wikipedia.org
Unlike Hangul's jamo, a Khitan phonetic symbol could represent not just a single vowel or consonant, but a CV or VC pair as well.
From the en.wikipedia.org
Unlike kanji, hiragana is a phonetic alphabet, which means that each symbol represents one sound only.
From the guardian.co.uk
The tie is a symbol in the shape of an arc similar to a large breve, used in Ancient Greek, phonetic alphabets, and Z notation.
From the en.wikipedia.org
Phonetic transcriptions that better depict pronunciation and which note changes due to grammar and proximity of other words require a symbol to show that the letter is mute.