Properly crediting individual names in a group.

Deepvoice: The way the credits should be listed on IMDb is the way they were listed in the original release of the film, which in this case would have been the theatrical version. Later changes to the credits should usually be irrelevant to IMDb.

The difficulty, though, is that the DVD version of the credits is easy to find and prove. I don't know how you can prove that your individual credits appeared in the theatrical release credits.

I also don't know why the producers would have changed the credits from theatrical to DVD versions. The easiest thing for them would have been to leave the credits just as they were.

My comment above was directed mostly toward the way your individual credits should be formatted based on the DVD release. But based on the theatrical release which is supposed to be the main source for IMDb's credits, I would say they should read as:

Dick Lyon ...  Barbershop Quartet  "Ain't Misbehavin"
Damon Sauer ... Barbershop Quartet  "Ain't Misbehavin"
etc., with no attributes needed.

So, on the German version of the DVD I suppose they didn't change the credits like they did with the English version (Please note this from the Credits info button) They would not have the members of the quartet's names if they were not credited individually by name.

http://www.buch.ch/shop/home/artikeldetails/bobby_jones_die_golflegende/EAN4030521387751/ID6127413.h...

Since this is the case. This is where the original confusion comes in.
Would this mean a individual IMDB page for each credited or click on add credit 4 times?

Deep: Go to the page for the film "Bobby Jones: Stroke of Genius", and click "Edit page".

On the next screen, on the Cast line, select "Add 4 credits" in the drop-down box. Scroll down and click "Continue".

On the next screen, you will see four lines, one for each person you will be submitting to add to the credits. Those lines are where you will fill in the group member names.

Just to clarify and make sure we're all doing the right thing...

This is just like the Beatles/Help! example but round the other way. So follow gromit82's advice and enter the individual credits for each member of the group, but you can also get the group on the page by adding a credit for Ain't Misbehavin with:
character Themselves
attribute (uncredited)

That will make sure that everyone can be found.

Thanks so much for clarifying Tim!