SBVR — Fact-types and templates (and subscripts)

In SBVR clause 8, subscripts occur in fact-type term entries. In clause 14, those subscripts are omitted from the fact-type term entries. This is inconsistent, apparently because the entries in clause 8 are doing double duty: as fact-type definitions and as SBVR Structured English templates.

Subscripts occurring in fact-type definitions (Glossary Fact Type entries) are not part of the entry for the fact-type. They are an accidental part of definition of the template for the corresponding form-of-expression.
A fact type is an abstract concept, and the glossary item apparently defines both the fact-type and a form-of-expression for the fact-type. That form of expression belongs to "SBVR Structured English", and there may well be other forms of expression for the selfsame fact-type in other languages. So the specification has to make this distinction very clear.
But the subscripts are not in fact a part of that form of expression, either. They are not keywords in the template itself. They are rather a lexical mechanism used to distinguish two roles in the template (and in the fact type) that happen to require the same underlying concept type. That is, in "concept#1 specializes concept#2"
SBVR defines the fact-type
"concept specializes concept",
and at the same time, defines the fact-type template:
"concept#1 specializes concept#2"
where "concept#1" designates a "concept" and "concept#2" designates a "concept". That is, "concept#1" is just a template parameter that lexically represents one role in the fact-type "concept specializes concept". For the template, "concept#1" could just as well have been called "parameter#1" or "x". "concept#1" is neither a "term" nor a "keyword"; it is a template parameter – a lexical stand-in that is to be uniformly replaced by one actual "term" or "name" in all uses of the template and in all occurrences in the corresponding definition. The current notation makes this confusing.
Note that this situation is not really different from "concept incorporates characteristic". The fact-type is "concept incorporates characteristic" and the template is "concept#1 incorporates characteristic#2", but we didn't happen to need the parameter-subscripts to distinguish the roles in this case, only because the concepts playing the roles are distinct.
Given the role of this standard, this notation is confusing, and marking the subscripts as keywords is technically wrong. SBVR can continue to use this notation only if it is very clear about the distinction between the fact-type
"concept specializes concept"
and the template
parameter#1 (concept) specializes (concept) parameter#2

• Proposed solution:

Clarification is needed. How to do it is not clear.

Clarify the meaning of subscripts used with placeholders. Expand the reference scheme for placeholders to support textual placeholders whose expressions use delimiting characters, subscripts and/or other marks. Make the use of a designation by a placeholder optional.
Clarify how fact type forms are distinguishable within a namespace.