1. For texts or elements laid out in multiple columns, the WWP indicates the number of columns using the “columns” keyword in the renditional ladder. This information should be recorded on the logical element containing the multiple-column layout. If an entire division of the text is in two columns, the rend= attribute on that <div> element should be:
<div type="chapter" rend="columns(2)">
The columns() keyword should not be used for pieces of text such as stage directions or parts of closers, in which multiple text components may be arranged laterally across the page. For information on how to encode these, see “Reading Order”.
2. Columns here refers to the existence of multiple flows of text on a single page, not to arrangements of text (such as lists or charts) in which columns are an implicit part of the arrangement of the information. As a general rule, a text should be considered to have more than one column (for renditional purposes) only if each individual column could appear on a page by itself without changing the intelligibility of the text. The most frequent pitfall is to encode a list as having multiple columns. Lists may be formatted so that the information they contain is arranged visually into column-like structures, but these are not columns in the sense meant by the “columns()” keyword. Consider the following examples:
a. A list of subscribers indicating the subscriber’s name and the number of books they bought.
b. A list of subscribers indicating the subscriber’s name, their residence, and the number of books.
In the first case, the list will naturally form itself into two columns, and in the second, the list will naturally form itself into three columns. However, these columns are not the ones intended by the columns keyword; the number of columns in these cases is implicit in the number of components in the list. Next, imagine that in the first case, the list was so narrow that the printer arranged it into three columns, so that across the top of the page there were the following headings:
name #books name #books name #books
In this case, the rendition for the list would be:
<list type="subscriber" rend="columns(3)">
3. To indicate a break within a column (similar to a page break), use the <cb/> element.