My comment was to other brothers who seemed to think that lines were something really different from pledge classes.

Bigs are still used with lines. The relationship between big/little (at least in my chapter) superceded that of the relationship between people who share your number. BUT the relationship between you and your number(s) is important because that gives you a special bond with brothers in other chapters.

Some chapters give an overall name to the line in addition to each members' individual line name.

Some chapters that have lines such as Alpha Gamma Gamma at CUNY-Hunter refer to their line as their class name (i.e. the Spring 2004 line [one of the tightest lines I've ever seen] was the Alpha Alpha pledge class)

For the most part there really is no one answer to any of these questions. It depends on the chapter.

I have a lot of trouble believing that the pledge process is identical between classes and lines. Of course, I haven't seen an APO line! :) I need to do that because it's very interesting to me now.

It is cool to hear how things are done other places.

No two pledge classes are alike so of course lines and pledge classes aren't identical. Al line at Beta Iota is going to be different from a line at Alpha Gamma Gamma and Mu Alpha and anywhere else they have lines. A pledge class at Beta Iota is going to be different from a pledge class at Kappa Beta or any other chapter that has pledge classes. Every chapter is different. Every line is different and every pledge class is different.