A number of guidelines or [[rubric]]s govern which icons are on which parts of the iconostasis, although there is some room for variation. There are also guidelines for who should enter or leave the altar by which door. These guidelines were developed over the course of many centuries, with both theologically symbolic and practical reasons for them.
Though they vary in size, shape and number of icons, the following is a basic layout of an icon screen which one might find in typical parish church.
[[Image:Iconscreen.png|center|Typical layout of an icon screen]]
#Icon of Saint John, the Prophet, Forerunner, and Baptizer of the Lord.
#Icon of the patron of the temple, or of its patronal feast.
holy doors (or the Royal Doors). These usually are a [[diptych]] of the [[Annunciation]]. Sometimes they may also have the icons of the four [[evangelist]]s.
#North door (the north and south doors are often called "deacon's doors"). This will usually depict a deacon, usually St. Stephen the Protomartyr, or an archangel, usually St. Michael.
#South door. The same as above, though if a deacon is depicted, it is usually St. Philip or St. Lawrence, and if an archangel, usually St. Gabriel.#These icons (when present) are usually
saints especially near to a parish or nation, such as Ss. Nicholas, George the Trophy-bearer, Demetrius the Myrrh-streaming, Sergius of Radonezh, Andrew the First-called, Herman of Alaska, or Seraphim of Sarov.
#This is usually the icon of the Mystical Supper, the last supper our Lord ate with his friends and wherein he instituted the Eucharist.