Sometimes you may have a column that contains inline HTML. A simple example of this is if you have a column called color and you want to display the color in the report. Your query would look like this:

SELECT '<span style="color:' || color || '">"' || color || '</span>' color
FROM my_colors

Note: That they're ways to get around this simple example using Report Templates and Column Formatting. I'm just using it for demo purposes

If you were to download this report the "color" column would contain all the html (i.e. span tags etc). This may confuse users since they expected to see "red, green, blue, etc..." in their download file, but instead see the colors wrapped in a lot of html.

A workaround that I've used is to create 2 columns: color_html and color

SELECT '<span style="color:' || color || '">"' || color || '</span>' color_html,
            color color
  FROM my_colors

And modify each report column's attributes:

Standard Reports

Interactive Reports

Now when a user downloads the report they'll get the non-html version of the column. This solution works in APEX 4.0 and APEX 3.x