The letter (Ъ, ÑŠ) of the Cyrillic alphabet is known as the hard sign (твёрдый знак ) in the modern Russian alphabet and as er golyam (ер голÑм, "big yer") in the Bulgarian alphabet. The letter is called back yer in the pre-reform Russian orthography, in Old Russian, and in Old Church Slavonic. Originally the yer denoted an ultra-short or reduced middle rounded vowel.