HACEK organisms are a subgroup of bacteria.

A háček ("ˇ", pronounced ), also known as a caron, is a diacritic placed over certain letters to indicate palatalization or iotation in the orthography of Baltic languages and some Slavic languages, whereas some Finno-Lappic languages use it to mark postalveolar fricatives (sh, zh, ch). It looks similar to a breve, but has a sharp tip, like an inverted circumflex (^), while breve is rounded. Compare Ǎ ǎ Ě ě Ǐ ǐ Ǒ ǒ Ǔ ǔ (hacek) with Ă ă Ĕ ĕ Ĭ ĭ Ŏ ŏ Ŭ ŭ (breve). When it is not available, in Finno-Lappic languages it can be substituted with 'h', e.g. 'sh' for 'š'.

The word háček means "little hook" in Czech. In Slovak it is called mäkčeň (i.e. "softener" or "palatalization mark"), in Slovenian strešica ("little roof"), in Croatian kvačica (also "small hook"), and hattu ("hat") in Fennic languages.

Usage

The use of háček (and the acute) for Latin characters was introduced by Jan Hus in the 15th century into the Czech language and today it is also used by the Slovaks, Slovenians, Croatians, Bosnians, Serbs, Upper Lusatian and Lower Lusatian Sorbs, Lithuanians, Latvians and of Fennic languages, Karelian and some Sami languages. It is also often used for international transliteration, particularly in Pinyin for Chinese, where it represents a falling-rising tone. Besides the háček and acute (čárka), the Czechs also use kroužek (ring).

Writing and printing haceks

In printed text, the caron combined with some particular letters is reduced to a small line (as in ť ď ľ Ľ). This only rarely happens in handwritten text. Although the small line may look like an apostrophe, that is definitely not the case. Using apostrophe in place of an caron looks very unprofessional though it is quite common on goods produced in foreign countries and imported to Slovakia or the Czech Republic (compare L' Ľ, t' ť, L'ahko Ľahko). Foreigners also sometimes mistake caron for the acute accent (compare Ĺ Ľ, ĺ ľ).

List of letters

A complete list of Czech and Slovak letters with the háček/caron:

• Č/č (pronounced /ʧ/ — similar to 'ch' in cherry, e.g. Československo which means Czechoslovakia)
• Š/š (pronounced /ʃ/ — similar to 'sh' in she, e.g. in Škoda )
• Ž/ž (pronounced /ʒ/ — similar to 's' in treasure, e.g. žal which means sorrow)
• Ř/ř (only in Czech: special fricative trill /r̝/, also transcribed as /ɼ/ pronounced roughly as a compound of trilled /r/ and /ʒ/, e.g. Antonín Dvořák  Cs-Antonin Dvorak.ogg^?)
• Ď,Ť,Ň/ď,ť,ň (palatals, pronounced /ɟ/, /c/, /ɲ/, slightly different from palatalized consonants as found in Russian): "Ďábel a sťatý kůň" which means "Devil and beheaded horse")
• Ľ/ľ (only in Slovak: pronounced as palatal /ʎ/: "podnikateľ" means "businessman")
• Dž/dž (pronounced /ʤ/ "džungľa" means "jungle")
• Ě/ě (only in Czech) indicates mostly palatalization of preceding consonant: "dě", "tě", "ně" is pronounced /ɟɛ/, /cɛ/, /ɲɛ/; but "mě" is /mɲɛ/, "bě", "pě", "vě" are /bi̯ɛ/, /pi̯ɛ/, /vi̯ɛ/

Of Baltic and Slavic languages, Belarusian, Croatian, Slovenian, Latvian and Lithuanian use Č/č, Š/š and Ž/ž.

Of Finno-Lappic languages, Estonian (and transcriptions to Finnish) use Š/š and Ž/ž, and Karelian and some Sami languages use Č/č, Š/š and Ž/ž. Notice that these are not palatalized, but postalveolar consonants. For example, Estonian kass (palatalized) is distinct from kaš (postalveolar). Palatalization is typically ignored in spelling, but some Karelian orthographies use an apostrophe (').

Other uses

The caron is also used in Mandarin Chinese pinyin romanization and orthographies of several other tonal languages to indicate the "falling-rising" tone (third tone in Mandarin). The caron can be placed on top of the following vowels:

• Ǎ/ǎ
• Ě/ě
• Ǐ/ǐ
• Ǒ/ǒ
• Ǔ/ǔ (also used in Belarusian to indicate sound like english "w")
• Ǚ/ǚ

The characters Ě/ě are a part of the Unicode Latin Extended-A set while the rest are in Latin Extended-B, which often causes an inconsistent appearance.

The recommendation in Finnish is to used š instead of "sh" and ž for "zh" in translitterations, e.g. Hovanštšina, not Hovanshtshina. However, as Finnish uses neither sound, and neither keyboards nor the ubiquitous ISO_8859-1 codepage support these characters, this recommendation is rarely followed.

Software

Unicode

For legacy reasons most letters which can carry háčeks exist as precombined glyphs in Unicode, but a háček can also be added to any letter by using the character U+030C COMBINING CARON: example š or ž, but also nonstandard combinations like b̌ or q̌.

TeX

In TeX, háček can be written using the sequence \v. For example, a č is written as follows:

 \v{c}

Macintosh

On Mac OS X's 'Extended' keyboard layouts the háček is typed by pressing option-v followed by the letter you want. The combination shift-option-v will produce a combining háček appended to the previous character.

Microsoft Word

In Microsoft Word, you can usually find letters with háčeks by clicking Insert → Symbol → Symbols. Select "(normal text)".

XFree86

In recent versions of XFree86/Xorg servers, letters with háček can be types as a compose sequence <compose> c <letter>, e.g. pressing Compose-key c e yields the letter ě.