edge index
A form of the INDEX consisting of
marks on the edges of the pages of a book produced
by means of printed rules that run to the edge of
the sheet (bled) and can thus be seen on the fore
edge of the closed book. Edge indexing has the
advantage of being part of the printing process,
and also allows the use of virtually unlimited
headings, as well as adding nothing to the overall
cost of binding. Its principal disadvantage is
that the user does not know what the mark on the
edge refers to while the book is closed. (234 )