Decani and cantoris

Decani and Cantoris are the sides of a church choir occupied by the Dean and the Cantor, respectively. The abbreviations "Dec." and "Can." are used. In English churches, the decani is typically in the choir stalls on the south side of the chancel, and the cantoris is on the left side.
The association of the Dean with the south side has propagated from the Sarum liturgical norm, a practice that then propagated through pre-Reformation England and Wales. There are some notable exceptions in the monastic cathedrals, where the senior cleric under the bishop was the prior; he often sat on the liturgical north. Hence, in Durham Cathedral, Ely Cathedral, St Davids Cathedral, Carlisle Cathedral, and Southwell Minster, decani is on the north.
While the cantoris side of the choir corresponds to the Gospel side of the altar, cantoris and decani properly refer only to sides of the choir, not to the sides of the altar. The arrangement of the cantoris and decani sections is called the "split chancel" model, which favors antiphonal and responsorial performance.