Information
Empty Pages
Detects empty pages in the PDF file.
Separated Pages
PDF Preflight detects whether there are separated pages in the PDF file that are independent of PDF/X-1a specified controls.
Multiple Pages
PDF Preflight detects whether the PDF file contains multiple pages.
Graphic element lies completely outside of the media box
PDF Preflight detects whether the PDF file contains graphic elements that are outside of the media box.
To remove all graphic elements that are outside of the media box select the Fix check box.
Report transparent element
PDF Preflight detects whether the PDF file contains transparent elements.
Selecting the Report transparent element check box allows you to specify which of the following Acrobat transparency settings PDF Preflight should check:

Select Enable/Disable All for PDF Preflight to check all of these settings.
Annotation
Annotations are included
Determines whether the PDF file includes any annotations. An annotation could be a note, link, bookmark, attachment, or movie or sound file.
To search for all annotations select Any annotation. To exclude the printer's mark or trap network annotations, select Except Printer's Mark or Trap Network annotations. Printer's mark and trap network annotations are allowed outside of the bleed box in PDF/X files.
To remove the annotations select the Fix check box.
Annotations are set to print
Determines whether the annotations in the PDF file will print.
To ensure that annotations don't print select the Fix check box and select Do not print annotations or select Remove annotations.
Layout
Measurement units
The default linear units used for page size are points.
Page size is not
Determines whether pages are the same size in the PDF file.
To confirm that all the pages in the PDF file are the same size select Equal for all pages.
To confirm that the media boxes of the pages are the size that you specify, select the second option beside the two boxes, and type the media box dimensions in the boxes.
To change the page size select the Fix check box. If you selected Equal for all pages and you want to set the page size to the bounding box, select Enclosing bounding box. The enclosing bounding box refers to the PDF media box.
To set the page size to dimensions that you specify select the second option, type the page dimensions in the boxes, and select an alignment option from the Align page content to list.
Page orientation is not equal for all pages
Determines whether pages are a combination of portrait and landscape orientations.
To change all pages to have the same orientation select the Fix check box, and select Portrait or Landscape according to your requirements.
Page box layout does not conform with <list>
PDF Preflight detects whether the page box layout in the PDF file does not conform with Press Layout or Screen Viewing Layout.
Select Press Layout or Screen Viewing Layout and enter the Minimum Trim to Bleed Margin and Minimum Bleed to Media Margin points.
PDF Preflight checks whether the document contains predetermined or sufficient bleed.
Select the Layout has crop box equal to trim box or Layout has no crop box or crop box is equal to media box option.
Scaling
Page scaling factor is used
PDF Preflight detects whether the PDF file contains page scaling.
Page scaling ensures that a page prints with the same scale factor that is displayed on the screen.
Bleed
PDF Preflight detects whether actual bleed values fall outside the acceptable values you defined.
Select Bleed detection: Page contains elements that don't have sufficient bleeds.
Set the minimium acceptable Top, Bottom, Left, and Right bleed values (in points), then select either Check elements that touch the trim box or Check elements whose distance from the inside edge of the trim box is less than <points> .
Select Consider image content when deciding if images have sufficient bleed if you want PDF Preflight to include images in the bleed detection process.