Languages, including English, have stylistic conventions for formatted text. The origins of the conventions may be for readability, for aesthetics, for commercial reasons, or for a mix of these. Some are now just considered to be good design without reference to the underlying reason. Books on typography or book design will usually cover a subset of possible problems, but even the reference books differ in what they consider to be a problem, the threshold for a condition becoming a problem, and even the terminology for describing a problem.
Automated analysis, introduced in Antenna House Formatter V7.0 and expanded in V7.1, can detect a range of error conditions:
Too many blank pages at the end of the document
The printing and binding method used for a book may require that the book is a multiple of 8, 16, 32, or even more pages. Extensions to the force-page-count property make this possible with AH Formatter V7.1. However, the forced page count can result in empty pages at the end of the document just to fulfil the requirement. Empty pages are a cost to the publisher with little or no obvious benefit.
Too many consecutive lines end with a hyphen
Too many consecutive lines that end with a hyphen increase the likelihood that a reader will either skip reading a line or read the same line twice. Both the Chicago Manual of Style (17th edition) and Elements of Typographic Style recommend a maximum of three consecutive lines that end with a hyphen.
Too many consecutive lines that all start or all end with the same word
This is similar to the problem with multiple consecutive lines that end on a hyphen. Multiple consecutive lines that start with the same word or multiple lines that end with the same word can result in a reader either skipping a line of text or rereading a line. The Chicago Manual of Style (17th edition) recommends a maximum of three lines that either start or end with the same word. Book Typography warns against multiple lines that end with the same word but does not provide a limit and does not mention lines that start with the same word.
Lines before or after current block
When a chapter does not start on a new page, there can be a requirement for a minimum number of lines either before or after the chapter heading. Book Typography recommends at least three lines above and below the chapter heading. This can usually be enforced using the widows and orphans properties, but not when, for example, the previous chapter ends with short lines of dialogue.
Page widow
A short last line of a block of text that is formatted as the first line on a page or column can affect readability.
Paragraph widow
A short last line of a block of text can affect readability. A secondary consideration is that many paragraph widows can add extra pages, and cost, to a document.
River
A river occurs where spaces on consecutive lines overlap, or nearly overlap. Rivers are more likely to occur in justified text than in text that is aligned to one side or is centred. A large or long river of white-space may interfere with comprehension of the text. People differ in their sensitivity to rivers, but it is often noted as problem for people with certain cognitive disabilities, including dyslexsia.
Unbalanced spread
It can be an aesthetic requirement that text blocks on facing pages are the same length.
White-space
Excessive white-space between words can affect readability.
The problems found by the automated analysis are reported as log messages. The Antenna House ‘analysis-utility’ project on GitHub provides scripts to process the error log and the document to generate either an analysis report or a copy of the formatted document that is annotated to show the locations of the errors.