SPINE

one bar per category split into two parts around a center axis. Needs: categories with two complementary parts (done/remaining, yes/no).

part-to-wholecomparison

DL-01 AGRAW

Use when

two-part splits compared across categories
reading which side of a balance each category falls on

Do not use when

more than two parts (CH-PTW-02)
parts that do not sum to a meaningful whole

See instead

3 or more parts per category: CH-PTW-02
graded agreement levels: CH-DEV-05

Alternatives

CH-PTW-02 (100% stacked for 3-4 parts)
CH-DEV-05 (agreement scales with 4 levels)

Rules

the split point sits on the center axis; bar width is constant
left part muted, right part primary
values printed at both outer ends
sides named above the first row, never a legend

Never do this

three or more segments
legends
rows normalized to different totals without saying so

QA before delivering

two parts per row
center axis drawn
sides named once
unit once
source present

Data shape

title	action title with a number
source	bottom-left always
unit	appended to first-row values (%, usually)
series_labels	[left_name, right_name], printed above the first row
categories	array of {label, a, b}; a+b normalized per row

Sample data (golden)

{
  "title": "Two of six systems clear 60% completion",
  "eyebrow": "SYSTEM COMPLETION",
  "source": "Source: completion database, wk 28",
  "unit": "%",
  "series_labels": [
    "Complete",
    "Remaining"
  ],
  "categories": [
    {
      "label": "Utilities",
      "a": 68,
      "b": 32
    },
    {
      "label": "Power",
      "a": 61,
      "b": 39
    },
    {
      "label": "Control",
      "a": 57,
      "b": 43
    },
    {
      "label": "Fire & gas",
      "a": 52,
      "b": 48
    },
    {
      "label": "Telecom",
      "a": 44,
      "b": 56
    },
    {
      "label": "Buildings",
      "a": 31,
      "b": 69
    }
  ]
}