The fact that Oracle lets you get away with using those doesn't mean that it is a good idea to use them anymore than the fact that MSIE lets you get away with sloppy HTML means that you should write sloppy HTML. If there's any chance that the schema will be ported to another RDBMS in the future (and the OP is asking questions about the long range), then it is better to avoid ISO/ANSI SQL reserved words. Another reason to avoid them is if the schema will be used with parsing, cataloging, or validating software which may or may not recognize them.