Appendix B Mapping Application Defined Name to XML Name (Normative)

Rules for mapping application defined name to XML Name

[1]         XML Name has two parts: Prefix and LocalPart. Let Prefix be computed per the rules and constraints specified in Namespaces in XML.

[2]         Let TAG be a name in an application. TAG is a sequence of characters of the application. Let N be the number of characters in TAG. Let T1 , T2 ,..., TN be the characters of TAG, in order from left to right.

[3]         Let M be the implementation-defined mapping of the characters of the application to characters of Unicode.

[4]         For each i between 1 (one) and N, let Mi be M(Ti).

[5]         For each i between 1 (one) and N, let Xi be the Unicode character string defined by the following rules.


[5.1]                       If Ti has no mapping to Unicode (i.e., M(Ti) is undefined), then Xi is implementation-defined

[5.2]                       If i <= N-1, Ti is '_' (underscore), and Ti+1 is 'x' (lowercase letter x), then let

Xi ::= '_x005F_'

[5.3]                       If N >= 3, T1 is either 'x' (lowercase letter x) or 'X' (uppercase letter X), T2 is either 'm' (lowercase letter m) or 'M' (uppercase letter M), and T3 is either 'l' (lowercase letter l) or 'L' (uppercase letter L), then

Xi ::= '_xFFFF_' T1

[5.4]                       If Ti is not a valid XML NCName character or if i = 1 (one) and T1 is not a valid first character of an XML NCName, then:

Let U1, U2 ,..., U8 be the eight hex digits (hexDigit) such that Ti is U+ U1 U2 ... U8 in the UCS-4 encoding.

hexDigit ::= [0-9A-F]


[5.4.1]             If U1 = 0, U2 = 0, U3 = 0, and U4 = 0, then

Xi ::= '_x' U5 U6 U7 U8 '_'

This case implies that Ti has a UCS-2 encoding, which is U+U5U6U7U8.

[5.4.2]             Otherwise, let

Xi ::= '_x' U1 U2 U3 U4 U5 U6 U7 U8 '_'

[5.5]                       Otherwise, let

Xi ::= Mi

That is, any character in TAG that is a valid character in an XML NCName is simply copied.

[6]         Let LocalPart be the character string concatenation of X1 , X2 ,..., and XN in order from left to right.

LocalPart ::= X1 X2 .. XN

[7]         Let XML Name be the QName per Namespaces in XML

QName ::= (Prefix   ':')? LocalPart

Normative References

XML 1.0 (Second Edition)
Extensible Markup Language (XML) 1.0, Second Edition, Tim Bray et al., eds., W3C, 6 October 2000. See

Namespaces in XML, Tim Bray et al., eds., W3C, 14 January 1999. See

Non-normative References

ISO/IEC 9075-14:200x(E)
ISO (International Organization for Standardization). Information technology - Database languages - SQL - Part 14: XML-Related Specifications (SQL/XML), working draft, dated 2001-06-18. See