Ever wanted to tag wall with a letter so you can then just write a summary with all wall types and their makeup? Well, in Revit 2010, you can. Easily.

What you are looking for is the Type Mark.

Once you have given your wall family type a Type Mark you can create a wall-schedule only with Type Mark and Type Comments. Don't itemize and sort after Type Mark and you get a nice list of all used wall types, sorted by their marks.

And now the big TIP: if you want to list multiple items under the comments (like the makeup of the wall), you can multiline them by pressing [ctrl]+[enter]. It won't show on the schedule, but once you place it on a sheet, the multiple lines will become visible.