Table 1.2 Example Name/Attribute Strings STRING LEGAL? COMMENT howdy Yes All valid characters; doesn’t start with a number or xml. _howdy123- Yes All valid characters; doesn’t start with a number or “xml”. _123-howdy Yes All valid characters; doesn’t start with a number or “xml”. 123howdy No Starts with a number. howdy everybody No Contains a space. howdy! No ! isn’t a valid character. xml-howdy No Starts with “xml”. howdy:everyone Yes, but . . . Use of a colon is forbidden, except in conjunction with XML namespaces. This is legal only if you have a namespace called howdy. Special Characters There are several characters that have special meaning in XML. From time to time, this will pose an inconvenience because you want to use these characters. The full set of special characters is described in Table 1.3. Table 1.3 Special Characters CHARACTER RESTRICTIONS WORKAROUND Not allowed in attribute Use &apos. values quoted by “ Not allowed in attribute Use &quote. values quoted by ‘ & Must always be escaped Use &amp. < Must always be escaped Use &lt. Introducing Oracle XSQL 19 271209 Ch01.F  12/9/02  2:00 PM  Page 19