Effect of adding properties before the visibility sections?

[n7800]

No visibility specifier declared means section public see reference manual:

For objects, three visibility specifiers exist: private, protected and public. If a visibility specifier is not specified, public is assumed.

The documentation is not entirely accurate here. The default visibility section of a class is public, however if the class is compiled with $M+ or descends from one that has that enabled it then the default section is instead published.

The documentation for objects (which don't have a "published" section) is quoted. However, the documentation for classes also doesn't provide this clarification, so I've created a report on the bug tracker.

Personally, I've been missing this explanation for a long time, as in practice, I've sometimes seen evidence of both, but didn't understand how it worked.