I noticed something interesting recently when looking at using Content Types in a Custom List in MOSS.

If you configure a list with Allow Management of Content Types...

...then add a field to the list, but clear the Add to All Content Types setting on the column...

...and now try and add or edit a list item.

You will notice that you cannot see the new column displayed when choosing any of the Content Types, and therefore cannot enter data into it.

You can, however enter data from the DataSheet view and add the column to lists.

I realise that this might not be a set of steps you will ever do, but what about people who do have access to List Settings?

I guess they have to clear the checkbox when adding a column, which is probably not going to happen often, but what if the Content Types on the list are read-only?

If the Content Types are read-only, adding the field without clearing the checkbox (ie. the default) results in the same behaviour as clearing the check-box.

While this issue is certainly not a critical one, I wonder how many phone calls starting with 'I added a field to my list, but now I can't enter data into it...' it will generate.