Tests the Entity Declared WFC, ensuring that a reference to externally defined entity causes a well-formedness error. SGML's NUTOKEN is not allowed. SGML's NUTOKENS attribute type is not allowed. Comma doesn't separate enumerations, unlike in SGML. SGML's NUMBER attribute type is not allowed. SGML's NUMBERS attribute type is not allowed. SGML's NAME attribute type is not allowed. SGML's NAMES attribute type is not allowed. SGML's #CURRENT is not allowed. SGML's #CONREF is not allowed. Whitespace required between attributes Whitespace required between attributes Only INCLUDE and IGNORE are conditional section keywords Must have keyword in conditional sections No whitespace before "?" in content model No whitespace before "*" in content model No whitespace before "+" in content model External entities may not have standalone decls. Comma mandatory in content model Can't mix comma and vertical bar in content models PE name immediately after "%" PE name immediately followed by ";" PUBLIC literal must be quoted SYSTEM identifier must be quoted Text declarations (which optionally begin any external entity) are required to have "encoding=...". EOF in middle of incomplete ETAG EOF in middle of incomplete ETAG Illegal markup (<%@ ... %>) Illegal markup (<% ... %>) Illegal markup (<!ELEMENT ... >) Illegal character " " in encoding name Illegal character "/" in encoding name Illegal character reference in encoding name Illegal character ":" in encoding name Illegal character "@" in encoding name Illegal character "+" in encoding name Text declarations (which optionally begin any external entity) are required to have "encoding=...". No space between PI target name and data Illegal entity ref in public ID Illegal characters in public ID Illegal characters in public ID Illegal characters in public ID SGML-ism: public ID without system ID SGML-ism: omitted end tag for EMPTY content XML declaration must be at the very beginning of a document; it"s not a processing instruction Comments may not contain "--" ATTLIST declarations apply to only one element, unlike SGML ELEMENT declarations apply to only one element, unlike SGML ATTLIST declarations are never global, unlike in SGML SGML Tag minimization specifications are not allowed SGML Tag minimization specifications are not allowed SGML Content model exception specifications are not allowed SGML Content model exception specifications are not allowed CDATA is not a valid content model spec RCDATA is not a valid content model spec SGML Unordered content models not allowed