A caron ( Ë ) or haÄ ek ( from ) , is a diacritic . A caron ( Ë ) or haÄ ek ( Ë hÉ ` Ë tÊ É k ) ( from Czech hÃ Ä ek , ) , also known as a wedge , inverted circumflex , inverted hat , is a diacritic placed over certain letters to indicate present or historical palatalization , iotation , or postalveolar pronunciation in the orthography of some Baltic , Slavic , Finno-Lappic , and other languages .