In earlier versions of RoboHelp in the Table of Contents you were able to identify books or pages that were new or had new information on them by displaying a red asterisk on them. However with the last couple of versions we have used (2015 and 2019) we have not been able to work out how to do this.
Does anyone know if this is still possible or is there a different way to do it now?
I think that's only available for Microsoft HTML Help. I think you had to set CHM as your primary output to get the option. Given you don't set a primary output in New UI, I figure it's probably no longer possible in New UI, but should be in Classic. (Although the asterisk wouldn't display in webhelp output, for example)
The asterisk says it's the image for homepage tiles, as used in the Indigo and frameless skins. I don't think that is right and have queried it. At the same time I have suggested it does allow user icons to be used for TOC items.
I suggest a feature request is submitted. Please follow this link to request features. https://tracker.adobe.com
Post the link to your feature request in this thread and others can vote for it. The more people who do so, the higher it gets prioritised.