Do you mean Object Styles? You can have custom style mapping using the Export Tagging within the Object Style Options dialog. That class name, along with a sanitized version of the class name will appear in the output HTML as classes and can be styled with custom CSS.
You can also target individual objects with their alt attribute.
More info: https://ajarproductions.com/pages/products/in5/answers/1454/custom-class-name?show=1454#q1454
I export images (no css), i mean directly in indesign like paragraphe / caracters / table / cells...But i think it's depend on the software... (i work with alternate layouts)
