Enable Export Feature in Custom Forms

In Order to Enable Export option, available in Oracle Application forms to export the data into Excel file.
In the custom form at form level trigger write the below code in When-New-Form-Instance trigger.
APP_SPECIAL.ENABLE('FILE.EXPORT', PROPERTY_ON);

Difference Between Bitmap and character mode report

Here is an example to help explain how Oracle Reports are designed and printed in both the bitmap and character-mode environments. Assume you wish to print "Cc" where "C" is a different font and a larger point size than "c" and is in boldface type (where "c" is not). In Oracle Reports Designer, bitmap mode, you can make "C" bold and in a different font and point size than "c". This is because you are generating postscript output. Postscript is a universal printer language and any postscript printer is able to interpret your different design instructions. In Oracle Reports Designer, character mode, the APPLICATIONS STANDARDS REQUIRE the report to be designed in ONE FONT/ ONE CHARACTER SIZE. Character mode reports generate ASCII output. In ASCII you cannot dynamically change the font and character size. The standard is in effect so a report prints as identically as possible from both conventional and postscript printers.