clarification, nonterm containing terms in ISO mixed with prefatory t…

…ext: metanorma/metanorma-iso#1040

author/iso/topics/markup.adoc

@@ -285,15 +285,46 @@ any intermediate sections are treated as subclauses.
 
 === Term grouping 1 (subclause 1)
 
-==== Term
+==== Term A
 
-==== Term
+==== Term B
 
 === Term grouping 2 (subclause 2)
 
-==== Term
+==== Term C
+--
+
+As a further complication: if there is any text in a term grouping, Metanorma is going
+to assume that you intended a systematic term after all. If you want to introduce discursive
+text (e.g. boilerplate) in a term grouping, that text has to be flagged the same way
+as it would at the start of a terms & definitions section, with a `[.boilerplate]` clause
+as discussed in link:/author/topics/document-format/section-terms#overriding-predefined-text[Overriding predefined text]:
+
+[source,asciidoc]
+.Encoding subclause groupings in a terminology clause in mixed order
+--
+== Terms and definitions
+
+=== Term grouping 1 (subclause 1)
+
+[.boilerplate]
+==== {blank}
+For the purposes of this document, the following terms and definitions apply:
+
+==== Term A
+
+==== Term B
+
+=== Term grouping 2 (subclause 2)
+
+==== Term C
 --
 
+Without the `[.boilerplate]` and `=== {blank}`, the "For the purposes of this document" will be assumed
+to be the definition of the term "Term grouping 1 (subclause 1)", and Term A and Term B will be assumed
+to be its subterms.
+
+
 === Combined terms and definitions
 
 The title of a top-level "`Terms and definitions`" clause is populated