The content model for the <etal> element
Many journal tag sets model the <etal> element as EMPTY, that is, the element has no content. Such an empty element is typically used as a place holder, for example, to generate the text “et al.” via a stylesheet. In this Tag Set, the element is usually used as an empty element, but the tag set also accommodates those journal Tag Sets that expect content inside <etal>, so the element is modeled with text content instead of as formally EMPTY and may contain text such as “Associates, co-workers, and colleagues”.
<!ENTITY % etal-model "(#PCDATA %etal-elements;)*" >
(#PCDATA | bold | italic | monospace | overline | overline-start | overline-end | roman | sans-serif | sc | strike | underline | underline-start | underline-end | named-content | styled-content | sub | sup)*