Put the source, data period and update date beside the table—not on a distant methodology page

A published data table should answer three questions without making the reader hunt:

1. Who produced the underlying data?
2. What period do the figures describe?
3. When was this table checked or changed?

Put those answers directly above or below the table. A general “Updated” stamp at the top of an article cannot tell readers whether the data changed or someone merely edited the page.

Use a compact metadata block

For a table drawn from one source, this is enough:

Source: Sports & Fitness Industry Association (SFIA), “U.S. Pickleball Participation Statistics,” citing the 2026 Topline Participation Report Data period: Calendar year 2025 Source publication date: Not stated on the linked page Table last checked: September 25, 2026 Table last updated: September 25, 2026 (initial publication) Measure: Estimated U.S. participants age 6+, not registrations or memberships

Metric	Estimate	Data period	Status
Americans who played pickleball	~24.3 million	2025	Survey estimate

SFIA reports 24.3 million U.S. participants in 2025 and says its annual participation research includes 18,000 respondents age 6 and older, with data collected monthly. That makes the figure a survey-derived participation estimate—not a player registry or a count of dues-paying members.

The distinction matters for the same reason that USA Pickleball membership and national participation should not appear as interchangeable totals.

A leading tilde is useful editorial shorthand for an approximate estimate, but it does not replace a status label or method note.

Keep five dates separate

“Updated September 25” is ambiguous. It could mean the article was copy-edited, the publisher checked the source, the source released new data or the value changed. Use separate labels:

• Data period identifies when the measured activity occurred: “2025” or “January–June 2026.”
• Source publication date identifies when the source released that edition. If the source does not provide a date, say so rather than inferring one from a copyright notice or file timestamp.
• Table first published records when the table initially appeared, if that is useful to the reader.
• Table last checked records the latest editorial verification against the linked source.
• Table last updated changes when a value, definition, source or substantive note changes. On first publication, label the date accordingly.

The page-level article updated date may differ from all five. Fixing a typo elsewhere in an article should not imply that its data table was rechecked.

This separation is consistent with established metadata practice. The EPA’s open-data guidance treats temporal extent, last update and formal release date as different fields. The W3C Data on the Web Best Practices separately recommends descriptive metadata, provenance information, version indicators and version history.

When a table combines sources

A single source note becomes inadequate when rows come from different surveys, municipal inventories or report editions. Add source and status columns:

Measure	Figure	Geography	Data period	Source	Status
Participation	…	United States	2025	SFIA 2026 Topline report	Estimate
Dedicated public courts	…	Named city	As of Sept. 1, 2026	Parks department inventory	Count
Total court locations	…	Named market	As of Aug. 2026	Directory export	Listed inventory

Link each report, dataset or municipal record in notes immediately below the table. Link to the exact source where possible, not merely the organization’s homepage.

The status column prevents unlike figures from appearing equivalent. A survey estimate, a government-maintained count and a commercial directory listing are different kinds of evidence. A broad directory total should not be presented as a verified dedicated-public court count.

For a downloadable spreadsheet, repeat the metadata in a cover sheet or table of contents so it travels with the file. The UK Government Analysis Function’s spreadsheet publication guidance says a contents table can include the data source, last-update date and next-update date. It recommends an associated metadata file when publishing a CSV for machine use.

Handle live tables carefully

A table linked to an automatically refreshed file needs two timestamps:

• Source data as of: the upstream dataset’s stated cutoff or modification time
• Table retrieved: when the publishing system fetched the file

Do not label the retrieval time “data updated” unless the upstream data actually changed. A publishing tool may retrieve the same file repeatedly. Datawrapper, for example, documents both scheduled downloads to its servers and direct loading from an external file, allowing a visualization to refresh without being republished.

If historical values can be revised, mark them provisional, revised or final and retain a short change log:

September 25, 2026: Replaced the 2024 estimate with the source’s revised value; method and geography unchanged.

That sentence is more informative than resetting an unexplained “last updated” date.

Minimum publication standard

Before publishing a pickleball data table, check that it includes:

• a direct link to the underlying report, dataset or official record;
• the source organization and exact edition, where stated;
• geography and measured population;
• the period the data describes;
• an estimate, count, listed inventory, provisional, revised or final label;
• separate checked and changed dates; and
• a revision note when a previously published value changes.

The purpose is not metadata for its own sake. It is to let a reader identify what a number measures, trace it to its source and determine whether a newer figure may exist.