Of course you're right, Don, when you assert:
It would be far easier to delete a separate footnote than to eliminate provisions that are thoroughly embedded throughout numerous paragraphs in the regulations.
The "footnote" scheme can seem to place that entry as something abnormal; an exception to the rule.
That's why there was great reluctance to use a "footnote" to encourage the use of digital modes in the failed segregation-by-bandwidth scheme -- knowing it would cast those modes in a negative light.
