New rule 47 is just a renumbering of the old rule 55 which prohibits intentionally putting trash in the water. I believe this has been interpreted as including sail stops, bands or gaskets used to keep a spinnaker from filling while hoisting. I've seen several instances where sailing instructions have changed rule 55 specifically to exempt "biodegradable materials used to band spinnakers" and I expect that some sailors on some classes of boats would characterize use of such stops in some conditions as a safety matter with no appreciable environmental impact.
But rule 86.1(a) has been changed to disallow changes to rule 47 by prescription and, extending into (b) and (c), by NOR, SI or class rules. So the SI exemption for biodegradable stops is no longer available.
However, rule 47 also states that "the penalty for a breach of this rule may be less than disqualification." Would it be kosher for NOR or SI to state that for a particular event (or class within an event) the penalty for use of biodegradable sail stops would be nothing? Essentially allowing use without changing the rule?