带冒号的 XML 语法是什么意思？
What does the XML syntax with a colon mean?
什么作用：
<rd:...> </rd:.....>
in XML格式的RDL文件的含义和用途呢？
任何人都请向我解释一下。我刚开始学这个。
XML 语法 rd: 是命名空间前缀，是命名空间 URI 的缩写。
XML 命名空间
XML 命名空间的用途在 Section 1, Motivation and Summary of the W3C Recommendation: Namespaces in XML 1.0 (Third Edition):
中有清楚的解释
We envision applications of Extensible Markup Language (XML) where a
single XML document may contain elements and attributes (here referred
to as a "markup vocabulary") that are defined for and used by multiple
software modules. One motivation for this is modularity: if such a
markup vocabulary exists which is well-understood and for which there
is useful software available, it is better to re-use this markup
rather than re-invent it.
Such documents, containing multiple markup vocabularies, pose problems
of recognition and collision. Software modules need to be able to
recognize the elements and attributes which they are designed to
process, even in the face of "collisions" occurring when markup
intended for some other software package uses the same element name or
attribute name.
These considerations require that document constructs should have
names constructed so as to avoid clashes between names from different
markup vocabularies. This specification describes a mechanism, XML
namespaces, which accomplishes this by assigning expanded names
to elements and attributes.
因此，与其他标准工作一样，在 RDL 中，命名空间允许创建词汇表，而不必担心与其他词汇表发生命名冲突。
什么作用：
<rd:...> </rd:.....>
in XML格式的RDL文件的含义和用途呢？ 任何人都请向我解释一下。我刚开始学这个。
XML 语法 rd: 是命名空间前缀，是命名空间 URI 的缩写。
XML 命名空间
XML 命名空间的用途在 Section 1, Motivation and Summary of the W3C Recommendation: Namespaces in XML 1.0 (Third Edition):
中有清楚的解释We envision applications of Extensible Markup Language (XML) where a single XML document may contain elements and attributes (here referred to as a "markup vocabulary") that are defined for and used by multiple software modules. One motivation for this is modularity: if such a markup vocabulary exists which is well-understood and for which there is useful software available, it is better to re-use this markup rather than re-invent it.
Such documents, containing multiple markup vocabularies, pose problems of recognition and collision. Software modules need to be able to recognize the elements and attributes which they are designed to process, even in the face of "collisions" occurring when markup intended for some other software package uses the same element name or attribute name.
These considerations require that document constructs should have names constructed so as to avoid clashes between names from different markup vocabularies. This specification describes a mechanism, XML namespaces, which accomplishes this by assigning expanded names to elements and attributes.
因此，与其他标准工作一样，在 RDL 中，命名空间允许创建词汇表，而不必担心与其他词汇表发生命名冲突。