A hacek or háček (pronounced "'hatchek") is a diacritic (also known as a "caron") placed over certain letters to indicate palatalization[?] in the orthography of some Slavonic languages, such as Czech, and the Baltic languages and Estonian. It looks like an inverted circumflex and its name means "little hook" in Czech.
... City Line (Great Northern & City Railway) remain open as mainline stations:
Great Missenden tube station[?]
Wendover tube station[?]
Stoke Mandeville tube ...