How to get multiline titles / subtitles in my page headers

You can configure the headers and footers in the config file.

See Page headers and footers.

By default, title, subtitle and footer are set to an array of three format strings, to be printed left, centered and right. These may also be set to an array of three part format strings, which will be printed on separate lines.

For example, to get multiple subtitle lines:

pdf.formats.title {
    title :    [ "" "%{title}" "" ]
    subtitle : [ [ "" "%{subtitle.1}" "" ]
                 [ "" "%{subtitle.2}" "" ] ]
    footer :   [ "" "" "%{page}" ]
}

If you have a single {subtitle: ...} this will be the same as the default case. An additional {subtitle: ...} will be printed on the second subtitle line.

If you have multiple {title: ...} lines, they may be printed too close to each other. You can increase pdf.spacing.title to get more space for the title lines, shifting the subtitle lines down.

You may also need to adjust pdf.headspace and pdf.margintop, see Page margins.