abstract:The letter yer (Ъ, ъ, italics Ъ, ъ) of the Cyrillic script, also spelled jer or er, is known as the hard sign (твёрдый знак ) in the modern Russian and Rusyn alphabets and as er golyam (ер голям, "big er") in the Bulgarian alphabet. The letter is called back yer in the pre-reform Russian orthography, in Old Russian, and in Old Church Slavonic.