In order to arrange quires and booklets into a volume, a compiler would often mark each folio with a symbol indicating its place within the volume. Commonly, each quire will be allocated a letter (a / b / c and so on) and each folio within that quire will be allocated a number (i / ii / iii and so on); so the signatures on the completed volume will begin ai, aii, aiii, aiv in the first quire, bi, bii, biii, biv, in the next quire, and so on through the volume. The way that manuscripts are constructed from groupings of folios necessitates this system though often, especially in earlier manuscripts, the system of signatures that appears in a manuscript will be ad hoc.