I suppose she means for you to save it as a PDF with version 1.4 compatibility, which supports "transparency."
1. Draw a rectangle. Solid fill, no stroke.
2. Draw another rectangle, partially overlapping it. Solid fill of a different color, no stroke.
3. Transparency Palette: Set the transparency mode to Multiply.
Now you have a document which contains "transparency" settings.
4. Save A Copy.... Select PDF as the format. In the resulting PDF Options dialog, select Press Quality from the Presets popup menu. Note that the Compatibility popup automatically selects Acrobat 5 (PDF 1.4). Turn OFF the Preserve Illustrator Editing Cababilities checkbox. Save this file as "PDF1-4.pdf".
5. Save A Copy... again. Use the same settings, except this time change the Compatibility popup to Acrobat 4 (PDF 1.3). Again, be sure to turn OFF the Preserve Illustrator Editing Cababilities checkbox. Save this file as "PDF1.-3.pdf".
6. Open the first PDF in Illustrator (not Acrobat, not Reader). Get the white pointer. Select and move the second rectangle (the one that you gave the "transparency" setting). Note that when you move it, it is still a rectangle, and is still transparent. Look at the Transparency Palette. Note that the transparency setting is still there. PDF version 1.4 supports transparency.
7. Open the second PDF in Illustrator (not Acrobat, not Reader). Get the white pointer. Select and move the second rectangle (the one that you gave the "transparency" setting). Note that when you move it, it is not a rectangle. It is an L-shaped path. Note there are now three separate paths, and none of them have any "transparency" settings.. They are simply filled with colors so as to appear as if they overlap and are transparent. That's because PDF version 1.3 does not support transparency.
I believe what the client means is that she wants it saved with transparency, which requires a certain level of PDF. You may read on here http://en.wikipedia.org/wiki/PDF/A where the PDF Reference Version 1.4 is mentioned, or on the Adobe website. Acrobat 5 or higher should ensure that.
Edit: Hi James.
I thought I was alone in this early hour.
Both you guys helped me a lot.
Geez, I've been feeling out of my depth.
Obviously the client has done this before, but
its all new to me. Wow, thaks a lot for the help.
For my part you are welcome, NDZooDZoo.