The process of attaching index tabs to the leaves
of a book, or the cutting, stamping, gouging or
printing of indices in the fore edges of books.
When tabs are used for the index, the top one is
cut larger than the others when the steps are
small, because. being at the top of the leaf, a
small step may break away during use unless it is
large enough to be secured firmly to the leaf. In
blankbook tab indexing, under average conditions,
certain letters of the alphabet will have more
accounts listed under them than will other
letters. Analysis of this had led to the
development of tables that give the proper number
of pages to meet the requirements of each letter.
Thus, more pages are required for the initial
letter S, followed by B (or vice versa in some
cases), then H, and so on down to X, which
requires the fewest.
Indices for reference books are usually of the
thumb type, while blankbooks generally have cut
through or tab indices.
In indexing format, a ONE-LETTER INDEX
usually consists of 24 letters or divisions, while
a TWO-LETTER INDEX
has 13 divisions. Some indices have supplementary
indices for the five vowels cut into the leaves of
each letter of the main index.
Although these terms are used, an index may be
made with any number of divisions and leaves to
each division, or may be cut through the entire
book. (264 , 343 )