U+02A8 Latin Small Letter Tc Digraph with Curl

The Wikipedia has the following information about this codepoint:

The voiceless alveolo-palatal sibilant affricate is a type of consonantal sound, used in some spoken languages. The symbols in the International Phonetic Alphabet that represent this sound are ⟨t͡ɕ⟩, ⟨t͜ɕ⟩, ⟨c͡ɕ⟩ and ⟨c͜ɕ⟩, and the equivalent X-SAMPA symbols are t_s and c_s, though transcribing the stop component with ⟨c⟩ (c in X-SAMPA) is rare. The tie bar may be omitted, yielding ⟨tɕ⟩ or ⟨cɕ⟩ in the IPA and ts or cs in X-SAMPA. This affricate has a dedicated symbol U+02A8 ʨ LATIN SMALL LETTER TC DIGRAPH WITH CURL, which has been retired by the International Phonetic Association but is still used.

Neither [t] nor [c] are a completely narrow transcription of the stop component, which can be narrowly transcribed as [t̠ʲ] (retracted and palatalized [t]) or [c̟] (advanced [c]). The equivalent X-SAMPA symbols are t_-' or t_-_j and c_+, respectively. There is also a dedicated symbol ⟨ȶ⟩, which is not a part of the IPA. Therefore, narrow transcriptions of the voiceless alveolo-palatal sibilant affricate include [t̠ʲɕ], [c̟ɕ] and [ȶɕ].

It occurs in languages such as Mandarin Chinese, Japanese, Polish, Serbo-Croatian or Russian, and is the sibilant equivalent of voiceless palatal affricate. U+107AB 𐞫 MODIFIER LETTER SMALL TC DIGRAPH WITH CURL is a superscript IPA letter.