Content Scorecard

Language Feature DTDs RELAX NG Schematron W3C XML Schemas
Unordered content Yes[a] Yes Yes Yes[b]
Simple datatypes Some[c] Yes[d] Yes[e] Yes[f]
Enumerations Some[g] Yes Yes Yes
Default values Some[g] Some[h] No Yes
Pattern matching No Yes[i] Yes[j] Yes
Exclusions Yes Some[k] Yes Some[k]
Pernicious mixed content Yes Yes Yes No
Empty mixed content No[l] No Yes No

[a] Using the "&" connector of SGML.

[b] At the top-level of an element declaration

[c] There are a tiny set of data types.

[d] Datatype library identified by URI

[e] The simple datatypes of XPath natively and others by expressions on the lexical and value spaces.

[f] W3C XML Schema Part II datatypes

[g] On attribute values only.

[h] Only on attributes and only with RELAX NG DTD Compatibility.

[i] If provided by the datatype library (e.g., W3C XML Schema Part 2: Datatypes).

[j] Not regular expressions, but using string and other functions in expressions.

[k] By content model manipulation

[l] Generates a warning.