D-010 Is the § 3.1 delta_pct a percentage or a fraction, and how far below zero may it go?

What the schemas do

A percentage, so 10 is a 10 % surcharge, and at least −100.

Options

• percent-from-minus-100 Chosen

  A percentage, so 10 is a 10 % surcharge, and at least −100.

• fraction

  A fraction, so 0.1 is a 10 % surcharge, and at least −1, like the metrics of D-005.

• unbounded-percent

  A percentage with no bound.

Why

The key is named pct, so a reader writes 10 for 10 %; reading it as a fraction would make 10 a 1000 % surcharge. D-005 makes rate metrics fractions because their names don't say percent; this name does. A change below −100 % would make the rate negative, which Rate forbids, so −100 is the lower bound and nothing else is.

What we ask the specification to state

State that delta_pct is a percentage, such as 10 for 10 %, and at least −100. Say which rate it applies to: the gross rate, presumably.

The specification lines it rests on

Each line is quoted as the record pins it. Expand an item to read the quote.

main

• § 3.1, the pricing key row L146 at 44dfaaf

  pricing | OPTIONAL | Delta per option beyond those included, as { option_id: { delta_cpm | delta_flat | delta_pct } }

With the open PRs

• § 3.1, the pricing key row L139 on main at 981a74e

  pricing | OPTIONAL | Delta per option beyond those included, as { option_id: { delta_cpm | delta_flat | delta_pct } }

What it shapes

main: PercentChange

With the open PRs: PercentChange