Suggested for Further Study
Create a DTD for a Bookmark List Markup Language (BLML). A bookmark list can contain folder elements and bookmarks. A folder element should have a name attribute. A bookmark element must have the following information associated with it: name, URI, and comment. The DTD must use the following entities:
A general entity (that is, an abbreviation for your full name as the author of the comments).
A parameter entity (that is, the name attribute is common between the folder and the bookmark elements).
Here's a suggestion for an advanced DTD study. Define an element called STUFF with the following constraints:
The element can have A, B, and C subelements.
The element must have at least one of those subelements.
The element cannot have any duplicates. For example, if you have an A, you cannot have a second A.
(HINT: a good solution will use only three particles.)
Add a namespace to your BLML DTD and in an instance of a BLML document.
Create a schema for the Bookmark List Markup Language.