It is important that you define the html export tag in Paragraph and Character Styles and also important is to work completely with styles.
CSS can be created outside of InDesign and used upon html export.
first, thanks for taking the time to reply to my post. Thanks for you advice; I completly overlooked the html export tag. Also, had no idea about a CSS file created outside Indesign can be used upon export, that's great. My main frustration was coming from the HTML Export Options box, which by default has certain settings. In my workflow, I batch export multiple files at the same time and I want to change those settings (for instance I do not want to see HTML after exporting, or want all the images left intact (resolution, colour space, optimization, original images format, etc. Is it possible to change these default Indesign settings?