How inserted phrases are punctuated

The convention

When an amendment adds a phrase to an existing list, the amending regulation almost never says how to punctuate the join, so the mapping supplies that separator by a fixed convention — matching the separator the surrounding text already uses at the insertion point — and leaves every other mark in the sentence exactly as enacted.

In practice: where the neighbouring items are separated by commas, the new phrase is joined with a comma, as a peer of the items around it. Where they are not, it is joined with a plain space. Nothing else in the sentence is touched — so where the list already carried a serial comma before its final or / and, that comma survives the insertion.

A worked example

O. Reg. 22/98, s. 33 amends the definition of building system in the Ontario Building Code 1997, Article 11.1.1.2.

Two different things are happening in that one line, and they are worth keeping apart. The comma we supplied is the one after plumbing system — the join, which the amendment left open. The comma before or is the serial comma the 1997 regulation already carried; we leave it alone, and the e-Laws consolidation drops it. Only that second comma is a difference from e-Laws, and it is not this convention’s doing — it is what happens when nothing is changed.

Where the convention does not apply

Matching the neighbouring separator is only right when the added phrase is a genuine list item. Some insertions are not: they attach to the term before them rather than extending the list, and they take a plain space even where a comma sits beside the anchor. For example:

• a parenthetical qualifier — (FT1 Rating)
• a phrase led by a coordinating conjunction — and Sentences 3.3.4.11.(11)…
• a subordinate clause — as if the glazed openings were unprotected openings

Each of these grammatically modifies the preceding term, so punctuating it as a peer of the list items would change how the provision reads.

Why this can differ from e-Laws

The official e-Laws consolidation also makes presentation choices about list punctuation, in both directions, without any amending regulation directing them:

• Dropping a serial comma the filing has. OBC 2006, Sentence 8.2.1.5.(1): O. Reg. 350/06 files “no Class 1, 2, or 3 sewage system”; e-Laws renders “Class 1, 2 or 3”.
• Adding one the print does not have. OBC 1997, Articles 2.7.2.1. and 2.7.2.2.: the filed text reads “Parts 3, 5, 6, 7 and 9”; e-Laws inserts a comma before and.
• Both within a single provision. OBC 1997, Article 1.1.3.2., where serial commas are added and dropped across the same definition list.

We note this not as a criticism — consolidating decades of amendments into readable text requires exactly these judgment calls — but because it is the same kind of choice our join convention is. The difference is that ours is written down here, applied uniformly, and confined to the mark the amendment left open.