Documentation says:
BoxType.primary Specifies the primary box appearance.
BoxType.separator Specifies that the box is a separator.
Nice, but what does it mean ? What does a "primary" box look like ? How is it different to a "secondary" box ?
I have tried both forms (in ASOC) and they look the same. So, is there a difference in how they look ?
Thanks.
Read the API documentation, read the human interface guide ...
Well, I know, RTFM. But, I did look – and in the post, I quoted the advice provided in the API documentation. As hinted at in my post, the advice gave little information on the topic. The declaration "NSBoxPrimary = 0" was useful.
The Human Interface Guidelines have good advice on best practices. Maybe I'm a bit dense but I couldn't find any description of the primary and separator box types in the HIG.
I've also Googled for a few hours trying to figure it out with no luck. The search tool in "developer.apple.com" only points to the API doco.