Foredge shelving (or fore-edge shelving) is a book shelving technique where the foredge, i.e., the part of the book opposite the spine, rests on the shelf.
Foredge shelving may damage the spine and joints of a book. A possible reason for doing it was that leaving the spine facing up makes it easier to see the call number, which is usually located on the spine.
The Northeast Document Conservation Center (NEDCC) recommends that books should never be stored on the foredge. Instead, it is recommended that either the shelves should be rearranged to accommodate the books standing upright, or the books should be moved to other shelves that can accommodate the books standing upright.[1]
In a historical context, fore-edge shelving means the practice of placing books on shelves with the fore-edges facing outwards.