Metelko introduced his alphabet in the book Lehrgebäude der slowenischen Sprache im Königreiche Illyrien und in den benachbarten Provinzen (Textbook of the Slovene Language of the Kingdom of Illyria and Neighboring Provinces, 1825).
Metelko was influenced by the ideas of Jernej Kopitar, a well-known linguist who also participated in the development of the modern Serbian alphabet (created by Vuk Karadžić, following Kopitar's ideas).
The difference between glottal and velar (/h/, /x/) is in fact not relevant to Slovene phonology, and therefore the letter was omitted by some authors.
In this alphabet, the various mid vowels are written using diacritics (é, ê, è, ó, ô, ò), but only in cases when it is necessary to distinguish two words (e.g. klóp 'bench' vs. klôp 'tick').
The IETF language tags have assigned the variant sl-metelko to Slovene in the Metelko alphabet.