Pete,
Most of the ACADE dialog boxes are the same regardless of which mode you are working in. However, the Insert/Edit dialog boxes are slightly different depending on whether you are working in IEC or JIC mode (or as you noted, you have the 'Combined Installation/Location and component Tag mode' option selected). You will notice that if you are combining the codes or if you are working in IEC mode, all instances of Installation are now Function. The current Help may not indicate this issue, but the Help file is complete in that it tells you what each option is and what it is used for.
The issue you've noted in your post was discovered after the Help was finished for 2005. I have already addressed this issue and have created additional Insert/Edit Help files for working in IEC mode, which will be available in future releases of AutoCAD Electrical.
I hope that I have answered your question and addressed any concerns. Please feel free to post any other questions pertaining to the Help.
Regards,
Heather Schwartz (Autodesk)