list column rendition
columns cb

Encoding of multi-column layouts using the columns keyword in the renditional ladder

For texts or text segments that are laid out in multiple columns, you can indicate the number of columns with the rend attribute, using the columns keyword. The number of columns is given as a numeric value. This information should be recorded on the element that logically contains 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)">

Columns here are considered as cases where the text flow is arranged sequentially into columns (with the text flowing from one column to the next), not to arrangements of text (such as lists or charts) in which columns are an essential 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. Similarly, 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.

To indicate a break within a column (similar to a page break), use the empty cb element.