When using ArchiCAD, it is quite common to export (save) PDFs of our projects, possibly using the Publisher tool.
Not many people take advantage of the ability to incorporate PDFs inside our projects, typically for documentation/annotation//specification aspect in a Detail, or on a Layout.
If you wish to place a portion of a PDF document inside an ArchiCAD project, you can use:

• The Drawing Tool
• Goto File > External Content > Place External Drawing

If using the 'Drawing' tool:

1. Left-Click once on the Drawing tool in the Toolbox
2. Left-Click once on the Floorplan, Worksheet or Layout
3. If placing on a Layout, choose the option to Link To 'an external source'
4. Using the dialog, browse to the location to the document, and Click 'OK'
5. The drawing will be placed where you initially clicked in the 2D window

If using the Pulldown menu:

1. Follow the Pulldown menu route, File > External Content > Place External Drawing
2. Using the dialog, browse to the location to the document, and Click 'OK'
3. Left-Click once on the Floorplan, Worksheet or Layout to place the document
4. The drawing will be placed where you initially clicked in the 2D window

(If the PDF is a multi-page PDF, then you will be prompted to choose the specific page from a given list.)

As the PDF is incorporated as a Drawing:

• The placed drawing is linked back to the original document, i.e. the content is not embedded, therefore not increasing the project size dramatically
• he PDF can be cropped/manipulated using Pet Palettes (as if it was a slab for example) so you can be very specific about the content you wish to show

A very simple ArchiCAD Project with a PDF included in the Layout book can be found here