Rule 4.3: Use a vertical list for complex text

What a checker looks for

Usually a deviation, and context can excuse it.

• Flag a long sentence that strings together multiple items or steps with commas/"and" where a vertical list would clearly be easier to read and understand — the standard sets no specific item-count threshold, so judge by length/complexity and readability rather than a fixed number of items.
• In an existing vertical list, flag a missing colon at the end of the introductory clause before the first item.
• Flag inconsistent capitalization, incorrect end punctuation (a comma or semicolon at the end of an item, a missing period on a full-sentence item, a period on a non-full-sentence item, or a missing period after the last item), or a list that mixes procedural (imperative) and descriptive items together.
• Flag a vertical list where an item does not connect clearly and correctly back to the introductory clause before the colon.

What this rule does not cover

• A list item that is not a full sentence correctly has no end-of-item period; only the final item in the list takes a period.
• A sub-list flattened into the main list at a single indentation level (rather than nested) is the compliant layout, not an error.

How to fix it

Convert the introductory clause to end in a colon, then list each item on its own line with a consistent marker, capitalized, each ending in a period only if it is a full sentence, with a period always after the final item.

Constraints on the fix

• Keep all items at a single list level — flatten any nested sub-list into a parenthetical or in-line note rather than nesting it (this is how the standard's own worked examples handle an item that itself has sub-items).
• Do not mix procedural and descriptive content within the same list.