§11.2.7

Maps and Treemaps

A tile with no printed value—estimate its area or leave it?

✅ NormativeSettled. The requirement holds as written.📄 Page ruleCan be applied from the page alone.Read §11.2.7 in the RFC ↗

The requirement

A treemap MUST be rendered with one row per tile: the tile's label and its printed value. Tile area MUST NOT be turned into a value: no axis calibrates it. A map with printed values per region MUST be rendered with one row per printed region–value pair. A shading-only map with a discrete legend MUST give each region whose fill matches one swatch unambiguously that legend class, copied verbatim.

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.

Treemaps

A tile's printed value is copied as printed. A tile that prints no value, only a comparator (<1%), or a truncated label (Re…) gets no estimated value: its printed text is kept as it is, and nothing is read from its area.

✅ SampleThe rule applies

Every tile prints its label and share`threat-report-2025_p29`

eight rows in reading order, left to right and top to bottom. The percent sign is printed raised beside each number and is written as a superscript. All tile text is set in a heavier weight.

Source page

Expected output

**Observed Intrusion Tooling by Category, 2024** **Ransomware-Related**
Ransomware	34^%
Other	16^%
Credential Stealer	12^%
Utility	10^%
Tunneler	7^%
Backdoor	10^%
Downloader	6^%
Dropper	5^%

✅ SampleThe rule applies

Eight tiles, every label copied whole, parenthesis and all`crypto_usage_report2024_p33`

Seven print a number and the eighth, Social, prints <1% — a comparator, not a value. Its row keeps the printed <1%; no value is estimated from the sliver it draws. The footer's logo, copyright line and page number are elided.

Source page

Expected output

**DeFi and stablecoins dominate crypto usage today — emerging categories include gaming and social** **Category breakdown by daily active addresses (all blockchains)**
Decentralized finance (DeFi)	34%
Stablecoins	32%
Infra (bridges, oracles, MEV, account abstraction, etc.)	14%
Token transfers	13%
Centralized exchanges	3%
Gaming	2%
NFTs	1%
Social	<1%

…

Active addresses can be associated with more than one category. Source: Caldrivane Chain Analytics as of 9/30/2024, excludes wallet-to-wallet transfers.

…

Maps

Two readable layers, each with its own place in the table (see also Geographic Maps (§12.2.4)):

Values printed per region or per pin — one row per printed pair: the region or callout text as the label, the printed value copied as printed. A callout on a leader line (DE 1) is read like any other.
Shading with a discrete legend — each region's fill is compared with the legend swatches, and the region takes the legend class verbatim. A region whose fill falls between two adjacent swatches is given no class.

Where a map's classes go. A choropleth MUST be one table with one row per region, in reading order: the region label, its printed value when it has one, and its legend class in a last column headed by the legend's printed title (no header row when the legend has none). A region with an ambiguous fill has an empty class cell. Where the region names are recognised from the outlines rather than printed, the region column's header carries data-recognised — see Geographic Maps (§12.2.4).

A checker judges a class on meaning: it accepts the class string, an equivalent range, or a value inside the class's range, and treats region-name variants (CO / Colorado) as the same region.

✅ SampleThe rule applies

Both layers on one page`apport_p19`

every state prints its seat count, and the fill classes its change, so each state's row holds both — 50 states. Five states are shown, then the rest; the DE 1 callout on a leader line is read like any other. Delaware's fill is too small to compare with the swatches, so its class cell is empty. The agency footer is elided.

Source page

Source: U.S. Census Bureau, Apportionment of the U.S. House of Representatives Based on the 2020 Census (public domain)

Expected output · excerpt

**Apportionment of the U.S. House of Representatives Based on the 2020 Census**
		Change from 2010 to 2020
TX	38	State gaining 2 seats
OR	6	State gaining 1 seat
WY	1	No change
CA	52	State losing 1 seat
DE	1
…

Total U.S. representatives: 435

Numbers represent reapportioned totals of U.S. representatives.

…

✅ SampleThe rule applies

No values anywhere — state abbreviations printed, six legend classes, no legend title`cdc_p3`

Each region takes its class: every state, DC and territory shown (about 53 regions). Four regions spread across the classes are shown, then the rest. The legend draws ≥35% as a > glyph over an underline bar; ≥35% is the reading, and a checker treats >35% as the same class. The source lines are cut off at the page edge and are elided.

Source page

Source: U.S. CDC, Behavioral Risk Factor Surveillance System (public domain)

Expected output · excerpt

20%-<25%

25%-<30%

30%-<35%

≥35%

…

Markdown

<table data-source="chart">
  <tr> <td>CO</td> <td>20%-&lt;25%</td> </tr>
  <tr> <td>CA</td> <td>25%-&lt;30%</td> </tr>
  <tr> <td>TX</td> <td>30%-&lt;35%</td> </tr>
  <tr> <td>MS</td> <td>≥35%</td> </tr>
<!-- … -->
</table>

<!-- … -->

❌ Counter-sampleLooks like it applies and does not — or a rendering got it wrong

Event pins over a regional map`regional-catastrophe-report-2023_p54`

Event pins over a regional map, each callout naming an event and describing its losses (Eco: USD1.9bn / Ins: USD240mn). The map's shading has no discrete legend to class regions against, and a pin's position is not a value, so the map gives no chart table: its printed text is transcribed as text. The data of this page is the loss chart beside the map, which is a chart table like any other; its bars print no values, so they are estimates on the 20-unit grid. The map's title, callouts and place names are elided.

Source page

Expected output · excerpt

…

**Eastern Region: annual losses (USD bn)**
	Economic Loss	Insured Loss
2011	92	18
2013	38	6
2015	41	7
2017	55	11
2019	47	9
2021	62	12
2023	58	10

Figure 36: Map of notable Eastern Region events in 2023 | Data and Graphic: Caldrivane Re

Sample sources2

Public-domain U.S. federal government source material.

U.S. Census Bureau, Apportionment of the U.S. House of Representatives Based on the 2020 Census
U.S. CDC, Behavioral Risk Factor Surveillance System

Rule id charts-maps-and-treemaps · charts types

Treemaps

Maps

Neighbouring rules, and how they differ

More