Tabs appear as single spaces in the output
You may have documents with content that is aligned at specific tab stops to give a desired look. For example, a tab-delimited table is a text-only solution for presenting data without the need for configuring a table object. When you convert such a document with ePublisher, that custom alignment is usually lost, as the tabs turn into spaces in the HTML output.
In this case, the problem lies not in ePublisher's conversion of your documents to HTML, but rather in the browser's lack of support for tab stops. We are passing those tab characters to the output, but most browsers render them as spaces (by W3C convention). As a result, there is no easy way to render tab-delimited tables in HTML output. The best option is to create a table object in your document and insert the content accordingly. FrameMaker has a "convert to table" option that will create a table object containing columns and rows that correspond to your tab-delimited text. With table column widths specified explicitly, we can create an HTML table with the same dimensions and appearance in your output.
There is also an HTML/CSS solution that could work for you. Since most paragraph styles are displayed as DIV tags in HTML, the white space (including tabs and multiple spaces) is lost. For the affected paragraph styles in the Style Designer, choose Text properties, and change the 'White Space' setting to "Pre." Alternatively, you can change the HTML > Tag setting to "Pre," but you could lose other formatting cues. When you regenerate your output, the tabs and spaces should be preserved for the "Pre"-designated paragraphs. It might also have other unwanted effects, but you'll have to test it with your documents to detemine if it is an appropriate solution.