[Bug 5409] Clarify use of term 'rule' in SML specification

http://www.w3.org/Bugs/Public/show_bug.cgi?id=5409

           Summary: Clarify use of term 'rule' in SML specification
           Product: SML
           Version: FPWD
          Platform: PC
        OS/Version: MacOS X
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Core
        AssignedTo: cmsmcq@w3.org
        ReportedBy: virginia.smith@hp.com
         QAContact: public-sml@w3.org


The "sch:rule" element is part of Schematron patterns. The SML spec uses the
term "rule" to indicate a set of Schematron constraints.  In other words, SML
'rules' are defined by using Schematron rules. In addition, the spec specifies
'rules' for determining validity. We should clarify the use of 'rules' in the
SML spec, particularly in section 5.