The introductory pages of electoral registers (not always scanned by Ancestry) often explain the different types of qualification. It sounds to me as though the qualifying property (owned but not lived in, in this instance) was a shop numbered "2" in a courtyard behind, or accessed via, no.4 Ryland Street. Checking other pages of the register may reveal some other similar terms and help confirm the interpretation. Checking large scale Ordnance Survey plans (1:500, 1:1,250 and 1:2,500 scales) in the relevant county archives or major library may clarify the layout of the buildings. The relevant county archives may hold rates records which would clarify the sequence of addresses, the use the properties were put to (presumably shop in this instance) and who was responsible for paying the rates. The 1901 Census (but not the 1911) sometimes lists non-inhabited properties such as shops so it may be worth trawling this street to find the courtyards off it.