Modeling also implies making decisions on the name of elements and attributes. As you can see, I like to use meaningful names. Others prefer to use meaningless names or acronyms. Again, as is so frequent in modeling, there are two schools of thought and both have very convincing arguments. Use what works best for you but try to be consistent.
Acronyms are less language-dependent.
A tool to help I find drawing trees on a piece of paper an exercise in frustration. Fortunately, there are very good tools on the market to assist you while you write DTDs. Furthermore, to convert the tree in a DTD, it suffices to save it. No need to remember the syntax, which is another big plus. InformIT offers a complete online community delivering information, technology, reference, training, news, and opinion to IT professionals, students, and corporate users.