token
represents tokenized strings.
The ·value space· of token is the
set of strings that do not
contain the
carriage return (#xD),
line feed (#xA) nor tab (#x9) characters, that have no
leading or trailing spaces (#x20) and that have no internal sequences
of two or more spaces.
NMTOKEN has the
following ·constraining facets·:
lengthminLengthmaxLengthpatternenumerationwhiteSpace
Escape Characters
Illegal XML characters have to be replaced by entity references.
If you place a character like "<" inside an XML element, it will
generate an error because the parser interprets it as the
start of a new element.
&lt;
<
less than
&gt;
>
greater than
&amp;
&
ampersand
&apos;
'
apostrophe
&quot;
"
quotation mark
Apostrophes, quotation marks and greater than signs are
legal, but it is a good habit to replace them.