Clarify usage of svrl:active-pattern/@role

[dmj]

svrl:active-pattern defines a @‍role attribute but the Schematron's sch:pattern has no such attribute.

[dmj]

Maybe the Schematron pattern should get a @‍role attribute? Rick over at schematron.com seems to indicate that such an attribute for a pattern is in line with the overall design:

Each assert or report element (and, in fact, rules, patterns, etc) can have a role attribute. The intention of this attribute is to allow the assertion etc to be categorized, and the prime categorization we might use is severity.