Should not remove "true" of tfield in UTS35 Appendix A

In
http://unicode.org/reports/tr35/#LocaleId_Canonicalization
5. Canonicalizing Syntax
....
Remove any type or tfield value of "true"

But if the true of tvalue got removed, the tfield is not longer valid because
transformed_extensions = sep [tT] ((sep tlang (sep tfield)*) | (sep tfield)+) ;

tfield = tkey tvalue; validity
tkey = alpha digit ;
tvalue = (sep alphanum{3,8})+ ;

so we should either
1) change
Remove any type or tfield value of "true"
to
Remove any type value of "true"
2) change the definition of tfield

Mark- please take a look at this.