Which parts of an XML document are case-sensitive?

<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> </script> All of it, both markup and text. This is significantly different from HTML and most other SGML applications. It was done to allow markup in non-Latin-alphabet languages and to obviate problems with case-folding in scripts which are caseless. Element type names are case-sensitive: you must stick with whatever combination of upper- or lower-case you use to define them (either by first usage or in a DTD). So you can't say ...: upper- and lower-case must match; thus and are two different element types; For well-formed files with no DTD, the first occurrence of an element type name defines the casing; Attribute names are also case-sensitive, on a per-element basis: for example and in the same file exhibit two separate attributes, because the different casings of width and WIDTH distinguish them; Attribute values are also case-sensitive. CDATA values (eg HRef="MyFile.SGML") always have been, but ID and IDREF attributes are now case-sensitive as well; All entity names (Á), and your data content (text), are case-sensitive as always