The palatal hook is a type of hook diacritic

Hook (diacritic)

In typesetting, the hook is a diacritic mark placed on top of vowels in the Vietnamese alphabet. In shape it looks like a tiny question mark without the dot underneath. For example, a capital A with a hook is "Ả", and a lower case "u" with a hook is "ủ". It functions as a tone marker...

 formerly used in the International Phonetic Alphabet

International Phonetic Alphabet

The International Phonetic Alphabet "The acronym 'IPA' strictly refers [...] to the 'International Phonetic Association'. But it is now such a common practice to use the acronym also to refer to the alphabet itself that resistance seems pedantic...

 to represent palatalized consonants. It is a small, leftwards-facing hook joined to the bottom-right side of a letter, and is distinguished from various other hooks indicating retroflexion

Retroflex consonant

A retroflex consonant is a coronal consonant where the tongue has a flat, concave, or even curled shape, and is articulated between the alveolar ridge and the hard palate. They are sometimes referred to as cerebral consonants, especially in Indology...

, etc.

The IPA recommended that esh

Esh (letter)

Esh is a character used in conjunction with the Latin Alphabet. Its lowercase form is similar to an italic long s ſ or an integral sign ∫; in 1928 the Africa Alphabet borrowed the Greek letter sigma for the uppercase form , but more recently the African reference alphabet discontinued it, using...

 ( ʃ ) and ezh

Ezh (letter)

Ezh is a letter in the International Phonetic Alphabet , representing the voiced postalveolar fricative consonant. It is also called the "tailed z". Example: vision . It is pronounced as the "s" in "treasure" or the "si" in the word "precision"...

 (ʒ) not use the palatal hook, but instead get special curled symbols: ʆ and ʓ. However, versions with the hook may have been used by some authors.

The palatal hook was withdrawn in 1989, in favour of a superscript j

J

Ĵ or ĵ is a letter in Esperanto orthography representing the sound .While Esperanto orthography uses a diacritic for its four postalveolar consonants, as do the Latin-based Slavic alphabets, the base letters are Romano-Germanic...

 following the consonant (i.e., ƫ becomes tʲ).

Computer encoding

Unicode

Unicode

Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

 includes both a combining character

Combining character

In digital typography, combining characters are characters that are intended to modify other characters. The most common combining characters in the Latin script are the combining diacritical marks ....

 for the palatal hook, as well as several precomposed character

Precomposed character

A precomposed character is a Unicode entity that can be defined as a combination of two or more other characters. A precomposed character may typically represent a letter with a diacritical mark, such as é...

s, including superscript letters with palatal hooks.

While LATIN SMALL LETTER T WITH PALATAL HOOK has been in Unicode since 1991, the rest weren't added until 2005. As such, font

Typeface

In typography, a typeface is the artistic representation or interpretation of characters; it is the way the type looks. Each type is designed and there are thousands of different typefaces in existence, with new ones being developed constantly....

support for the latter characters is much less than for the former.

Appearance	Code point	Name
	U+0321	COMBINING PALATALIZED HOOK BELOW
	U+1D80	LATIN SMALL LETTER B WITH PALATAL HOOK
	U+1D81	LATIN SMALL LETTER D WITH PALATAL HOOK
	U+1D82	LATIN SMALL LETTER F WITH PALATAL HOOK
	U+1D83	LATIN SMALL LETTER G WITH PALATAL HOOK
	U+1D84	LATIN SMALL LETTER K WITH PALATAL HOOK
	U+1D85	LATIN SMALL LETTER L WITH PALATAL HOOK
	U+1D86	LATIN SMALL LETTER M WITH PALATAL HOOK
	U+1D87	LATIN SMALL LETTER N WITH PALATAL HOOK
	U+1D88	LATIN SMALL LETTER P WITH PALATAL HOOK
	U+1D89	LATIN SMALL LETTER R WITH PALATAL HOOK
	U+1D8A	LATIN SMALL LETTER S WITH PALATAL HOOK
	U+1D8B	LATIN SMALL LETTER ESH WITH PALATAL HOOK
	U+01AB	LATIN SMALL LETTER T WITH PALATAL HOOK
	U+1D8C	LATIN SMALL LETTER V WITH PALATAL HOOK
	U+1D8D	LATIN SMALL LETTER X WITH PALATAL HOOK
	U+1D8E	LATIN SMALL LETTER Z WITH PALATAL HOOK
	U+1DAA	MODIFIER LETTER L WITH PALATAL HOOK
	U+1DB5	MODIFIER LETTER T WITH PALATAL HOOK