*A check digit is a form of redundancy check used for error detection, the decimal equivalent of a binary check bit. It consists of a single digit computed from the other digits in the number. The method for the ten-digit code is an extension of that for SBNs, the two systems are compatible, and SBN prefixed with "0" will give the same check-digit as without – the digit is base eleven, and can be 0-9 or X. The system for thirteen-digit codes is not compatible and will, in general, give a different check digit from the corresponding 10-digit ISBN, and does not provide the same protection against transposition. This is because the thirteen-digit code was required to be compatible with the EAN format, and hence could not contain an "X".*

^{A nested list is a numbered or bulleted list with subordinate (usually indented) numbered or bulleted lists. Rather than just a list of numbered items (1,2,3...), a nested list may have item 1, then indented items numbered a,b,c or i,ii,iii or some other numbering method before the main number 2. With numbering styles you can achieve any combination of numbering formats you want. }

*The above steps are the most basic way to add a very basic page number, but if you follow a few tricks then you could save yourself even more time and get the job done even faster. For one thing, the page number you’ve added is only for one page, and if you used that method you’d spend ages adding page numbers to the whole document. To add page numbers to all pages quickly and format them all equally, follow these steps:*

_{If you’re producing any kind of numbered items in-house that are multiple-up on a sheet where you need to control all the variables to meet your production needs, the autonumbering feature through numbered lists is the way to go! Just step and repeat away & InDesign will do all the work. No need to fool with a seperate “numbers” file or deal with a data merged document. I think it’s by far the best option for basic numbering. }

a concept of quantity that is or can be derived from a single unit, the sum of a collection of units, or zero. Every number occupies a unique position in a sequence, enabling it to be used in counting. It can be assigned to one or more sets that can be arranged in a hierarchical classification: every number is a complex number; a complex number is either an imaginary number or a real number, and the latter can be a rational number or an irrational number; a rational number is either an integer or a fraction, while an irrational number can be a transcendental number or an algebraic numberSee complex number, imaginary number, real number, rational number, irrational number, integer, fraction, transcendental number, algebraic number See also cardinal number, ordinal number