Docbook / XML 对 ID / IDREF 的限制

Question

在我的（生成的）docbook 文件中，我得到了一个以数字开头的 ID / IDREF 对（比如 015_code 具有属性 xml:id / linkend，因此发出警告（XMLMind in这种情况):

bad value for attribute "id" from namespace "http://www.w3.org/XML/1998/namespace"

在书中"XML in a nutshell"我读到：

ID numbers are tricky because a number is not an XML name and therefor not a legal XML ID. The normal solution prefixes the values with an underscore or common letter.

这个解决方案对我有用，但在查看我的示例时 015_code 这不是一个数字，所以我的问题：

我的解释/引用不正确吗，ID / IDREF 不能以数字开头
这可能是 XMLMind 中的错误

Answer 1

你的第一个要点是正确的； ID/IDREF 不能以数字开头。该值必须是有效的 Name...

Names and Tokens

[4]   NameStartChar ::=   ":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
[4a]  NameChar      ::=   NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040]
[5]   Name          ::=   NameStartChar (NameChar)*
[6]   Names         ::=   Name (#x20 Name)*
[7]   Nmtoken       ::=   (NameChar)+
[8]   Nmtokens      ::=   Nmtoken (#x20 Nmtoken)*

来自 https://www.w3.org/TR/REC-xml/#sec-attribute-types ...

Validity constraint: ID

Values of type ID must match the Name production. A name must not appear more than once in an XML document as a value of this type; i.e., ID values must uniquely identify the elements which bear them.

和

Validity constraint: IDREF

Values of type IDREF must match the Name production, and values of type IDREFS must match Names; each Name must match the value of an ID attribute on some element in the XML document; i.e. IDREF values must match the value of some ID attribute.

Docbook / XML 对 ID / IDREF 的限制

Docbook / XML restrictions for ID / IDREF

xml

docbook