Topic Name Derivation Is Undefined for Subtree Filters

[ahassany]

Section 3.2 defines topic naming using absolute-schema-nodeid extracted from filters, and Figure 3 shows an example only for an XPath filter. For subtree filters, the absolute-schema-nodeid must be derived differently (by tracing the containment path through the XML hierarchy of the filter). No procedure or example is given for topic naming from a subtree filter. This leaves Section 3.2.1's normative MUST ("The YANG absolute-schema-nodeid MUST be derived from subtree and xpath filter data") without a corresponding algorithm for the subtree case.