Wow, I can't believe I'm defending svn....
But as far as I understand (and as far as I've been *using* it for several years now), there are not "specially named directories". There is a user-created convention of directory names and locations..
But underneath, there's NO difference between a tag directory and a branch directory.. (Which _annoys_ me, since I wish I could "lock" tag directories so I don't accidentally check into them, which I think I did once.. then undid of course..)
I guess this is a case of the grass is greener on _your own_ side of the fence.. Since git is reaaaaallly complex to me (and svn is complex compared to cvs, but I've MOSTLY gotten over that part).