No audible release

A stop with no audible release, also known as an unreleased stop or an applosive, is a stop consonant with no release burst: no audible indication of the end of its occlusion (hold). In the International Phonetic Alphabet, lack of an audible release is denoted with an upper-right corner diacritic (U+031A ̚ COMBINING LEFT ANGLE ABOVE (HTML ̚)) after the consonant letter: [p̚], [t̚], [k̚].[1]

No audible release
Entity (decimal)̚
Unicode (hex)U+031A

Audibly released stops, on the other hand, are not normally indicated. If a final stop is aspirated, the aspiration diacritic ◌ʰ is sufficient to indicate the release. Otherwise, the "unaspirated" diacritic of the Extended IPA may be employed for this: apt [ˈæp̚t˭].