With all due respect, I think YOUR the only one confused. If you had taken the time to fully read each post, the answer your seeking would have answered itself.

My first post said "I think I remember reading somewhere that it's an H3. Is this correct?" (obviously I was way off)

The answer was given in the subject line of the next post when Andrew said "It's an HB4". I think you missed reading the subject line.

Then I asked "Is an HB4 the same as a 9006" - the reply was yes. Thus the mystery was solved.

Since I understood this, I went out and bought myself some nice, xenon white fog light bulbs in size 9006.

The fog light bulbs are HB4 OR 9006 - END OF STORY.