An unexpected benefit of having CSS inside XSLT templates is that you can copy snippets of XSLT from one project to another, perhaps to implement Web-page controls or other common functionality, and the style is carried with them too. You could also do this if you had the CSS before the individual XSLT templates instead of inside them, but in that case you would have the possibility of missing the styles for the first template, and either the template would be separated from any xd:doc elements preceding it, or the CSS would be before the xd:doc elements and hence separated too far from the body of the template to reap the benefits of CSS Within.

The CSS Within approach relies on the CSS cascade mechanism: it is because of this that is not necessary to specify full styles for each generated element. This also means that a generated element that can appear in multiple contexts may need multiple css:ruleelements for the different contexts. As an alternative, the base styles can be placed in the template generating the ancestor element, and this relationship can be made specific with a ref= attribute on the individual css:rule elements to show the dependency. This makes no difference to the generated CSS, but helps the human maintainer of the stylesheet understand what has been done and keep it up to date. The XSLT implementation does currently check the ref attributes.