According to the Namespaces REC, a processing
instruction target name must not contain a colon.
AElfred is not rejecting a name that contains a colon,
but such a name is never matched by a Saxon stylesheet.
I am fixing this problem by rejecting source documents
that contain a colon in a PI name. But they will not
be rejected if this occurs in the DTD, because (a) an
XSLT processor is supposed to ignore PIs in the DTD,
and (b) the XHTML specification uses PIs containing
colons in its DTD.
Present in 6.5.1 and 7.0.
Source code fixed in both branches (module
ContentEmitter, method processingInstruction).