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§11.2.1

Bars and Histograms

One bar, one rule—but what is a histogram's category?

✅ NormativeSettled. The requirement holds as written.📄 Page ruleCan be applied from the page alone.Read §11.2.1 in the RFC ↗

The requirement

A bar chart MUST be rendered as a chart table with one value per bar: one row per category, one column per series. A histogram is a bar chart whose category is the bin: a bin the axis does not label MUST still get its row, labeled by its axis value, and a labeled position with no bar MUST hold 0.

When it applies

  • A single series gives a two-column table — see the full example in Values and Tolerances (§11.1.4).
  • Grouped bars give one column per legend series — see the full example in Labels (§11.1.2).
  • Horizontal bars change nothing: the category axis simply runs vertically, and rows follow it top to bottom.
  • A highlighted or average bar (EU average, shaded behind the rest) is an ordinary row. An average line is reference ink and adds nothing to the table (see Multiple Charts and Reference Ink (§11.1.3)).

Reading the examples. Each one pairs a source page with the output the rule expects. ✅ Sample: the rule applies. ❌ Counter-sample: it looks like it applies and does not, or a rendering got it wrong. A non-conforming output, in red, is shown only for contrast. … marks content left out of an excerpt.

Histogram bins

Printed bin labels are copied verbatim, catch-alls included (> 15000). When the axis labels only every other bin, the unlabeled bins still exist: each gets a row labeled by its axis value — 2000 between the ticks 1500 and 2500 on an axis labeled every $1 000. A bin that no printed calibration reaches is not locatable (see Cover Every Data Point (§11.1.1)).

01

✅ SampleThe rule applies

Bins every $500catastrophe-review-2025_p4

Bins every $500, labels every $1 000, a printed catch-all, and one labeled position (1500) with no bar. Full coverage is 29 rows: 1500 holds 0; the unlabeled bins are labeled by their axis values (2000, 3000 …); every count is an estimate against the 20-unit grid. The catch-all keeps its printed space (> 15000). The value axis title heads the single value column; the category axis title heads the label column.

Source page
Bars and Histograms — Bins every $500. Source page.
Expected output
Distribution of premium per policy in Florida at zip-code level, USD, 2022
Premium per policy in USD Number of zip codes in Florida
1500 0
2000 48
2500 125
3000 78
3500 58
4000 39
4500 36
5000 23
5500 18
6000 14
6500 14
7000 9
7500 9
8000 6
8500 6
9000 5
9500 11
10000 2
10500 3
11000 5
11500 1
12000 8
12500 4
13000 3
13500 4
14000 3
14500 3
15000 2
> 15000 21

Source: Caldrivane Institute, state insurance filings

Bars and Histograms · Source page

Bins every $500

Bars and Histograms — Bins every $500. Source page.

Progress and target bars

A goal statement with a single bar, its current value marked on it and the target at its right end, is a one-row bar chart, not a chart type of its own. Its chart table MUST hold the current value, the target and the axis end-points: the bar's meaning is relative to its scale, and 7 against 8 or 42% against 50% is only legible with that scale kept.

02

✅ SampleThe rule applies

goal cards with progress bars

Three goal cards separated by rules. Each bar marks its current value (40%, 7, 42%, each with the year 2024 beneath it) against a scale from its start (0%, 0) to its target (100% with 2030 Target, 8 with 2025 Target). The rows follow the axis: start, current value, target. The third card's scale end-points fall below the crop and are not shown, so its table holds only the current value.

Source page
Bars and Histograms — goal cards with progress bars. Source page.
Expected output

Goal

Replenish all our corporate freshwater withdrawals in high-stress locations by 2030.

Progress
0%
2024 40%
2030 Target 100%

Goal

Certify all company-owned data centers to the Regional Water Stewardship Standard by 2025.

Progress
0
2024 7
2025 Target 8

Goal

Increase supplier participation in the Supplier Water Efficiency Program, supporting a 50 percent average water reuse rate by 2030.

Progress
2024 42%
Bars and Histograms · Source page

goal cards with progress bars

Bars and Histograms — goal cards with progress bars. Source page.

Look-alike

Two similar pages that call for different decisions. Synthetic, for teaching the boundary.

A highlighted average bar and a dashed average line. Which one gets a rule?

A

An average drawn as a bar

ItalyEU averageGermany
The convention

An ordinary rule. Highlighting is styling.

B

An average drawn as a line

10-yr avg
ItalyFranceGermany
The convention

Reference ink. No rule.

Look at the structure. What evidence changes the answer?

More

Rule id charts-bars-and-histograms · charts types