Rule 83.Supplemental Rules

Rule 83 is the ruleset's acknowledgement that it does not cover everything, and it grants two powers in descending order of formality.

Supplemental rules

Any court whose procedure is regulated in whole or in part by these rules may from time to time make and amend supplemental rules, or continue in force existing rules, governing its procedure — not inconsistent with these rules.

The consistency limit is the whole of the constraint. There is no approval requirement in the rule's text, no notice-and-comment step, and no list of subjects. Massachusetts does have Supplemental Rules of the Probate and Family Court, which are a separate ruleset and are not carried on this site.

Case-by-case regulation

The second sentence is narrower and more immediate: in instances not provided for by rule, each said court may regulate its practice in a manner not inconsistent with these rules and the said supplemental rules.

Note the ordering that produces. A court looks first to these rules, then to its supplemental rules, and only then regulates its own practice — and each layer must be consistent with the ones above it.

Rule 81(e) does similar work from the other direction, telling the court how to proceed where no procedure is specifically prescribed. Rule 82 sets the limit both share: neither power reaches jurisdiction or venue.