You must specify a unique output filename when you use a topic more than once in a publication that uses the HTML5 output format. The HTML5 output format support breadcrumbs at the top of each topic. If you use a topic more than once in a publication and you do not use the copy-to attribute to specify a unique output filename, the breadcrumbs for each instance of the topic will include multiple paths.
Apply the copy-to attribute only on the additional instances of the topic. However, you can use the copy-to attribute for every instance of the topic.
Note:
The copy-to attribute might fail the Avaya DocPortal output generation, therefore, use it only when required.
