For detailed information on PDF structure, see the documents on the Adobe PDF Technology Center at www.adobe.com/go/learn_acr_pdftechnology_en (English only). If you have advanced knowledge of the PDF file format, examine the internal structure of the PDF and its fonts for technical reasons for a preflight mismatch. Preflight includes three options for in-depth inspection of a PDF. Technically skilled users can use these tools to analyze the objects and fonts that caused a mismatch.
In-depth knowledge of font internal structures, and font specifications for Type 1, TrueType, and OpenType fonts is important. The font specifications are listed in the bibliography of the guide.
Note:
You can navigate the PDF and fonts in the windows that appear, but you can’t edit the PDF structure or fonts.
View the structure of a PDF, as defined by content streams and cos objects, in a tree array. (Content streams represent pages, form XObjects, Type 3 font characters, and the appearance of comments and form fields. Cos objects include such items as color space, images, and XObjects.)
Check PDF syntax, view the results of a fixup, or determine the cause of a mismatch. Choose between five view modes that organize content streams in different ways. You cannot edit the PDF in the Internal PDF Structure window.
Note:
Do not confuse the internal structure with the logical structure in tagged PDFs that improves accessibility for low- or non-sighted readers. The internal structure is a superset of all objects in the document, including tags.
View the internal structure of embedded fonts in a PDF in greater detail than the preflight results with a graphical view that shows the outline and coordinates of each glyph. You can determine the source of various preflight problems, such as mismatches caused by inconsistent glyph widths.
Before you can browse the internal font structure, you must run a preflight check.