| CDATA |
The attribute value is regular
character data. Example:
a required language attribute
for the book element contains regular character data:
<!ATTLIST book language CDATA #REQUIRED>
|
|
| ID |
The attribute value must be a unique identifier.
Example:
every author element must have a
unique authid:
<!ELEMENT author (#PCDATA)>
<!ATTLIST author authid ID #REQUIRED>
|
|
| IDREF |
The attribute value must correspond to an existing ID.
It "points" to another entry.
Example:
The authref attribute of the book
element "points" to the author element with
a corresponding authid attribute.
<!ELEMENT book (#PCDATA)>
<!ATTLIST book authref IDREF #REQUIRED>
|
|
| NMTOKEN |
A name token is like CDATA but limited to
letters, digits and hyphens; no spaces, punctuation, etc.
It must begin with a letter.
Example:
<!ATTLIST book isbn NMTOKEN #IMPLIED>
|
|
| ENTITY |
The attribute value must be an entity name.
(Detailed in the next section.)
Example:
insert an image, where the image name is
a declared entity:
<!ATTLIST logo image ENTITY #REQUIRED>
|
|
enumerated
values |
Attributes can have predefined values:
<!ATTLIST date day
(mon|tue|wed|thu|fri|sat|sun) #IMPLIED>
|
Only values specified in this list are valid.
|
