titling figures

old style figures in titles


So everyone I look, it seems that if you're going to use old style figures at all in a work, then anywhere titling figures appear, it'd better be in an all caps environment. But if we're to really stick with the

old style figures : titling figures :: lowercase : upper case

analogy, wouldn't that mean the '7' in

Chapter 7

ought not to have that descender? After all, in words, it would be "Chapter Seven." (It actually makes me pause when I see "September 23, 2010" and all the numbers are text figures. That can't be good, right?) But then, following the rule strictly,

Chapter 11

ought to have two different styles for the two different '1's. !!! =(