File Naming Convention
Data for Canada: File Naming Convention (DFC-FNC)
Background
See Statistics Canada’s geographic hiearchy and use the Census of Population 2021 Dictionary to understand their conceptual model of representing Canada.
.
1. The Current Schema
All published datasets must adhere to the following structure to ensure files are machine-parsable, sortable by region, and identifiable by human readers. This file naming convention will be modified as we solidify our processes.
Syntax
[iso-region]_[source-identifier]-[DGUID]_[packages_collection]_[iso-date]_[variant]_[version].[extension]
Example:
ca-ab_city-of-edmonton-2023A00054811061_orthoimagery_2023_075mm_v0.0.1.pmtiles
Component Breakdown
| Segment | Definition | Format / Rules | Example |
|---|---|---|---|
| 1. ISO Region | The ISO 3166-1 alpha-2, which is a two-letter country code, or ISO 3166-2 which identifies the principal subdivisions (ex. provinces, states, etc.) | Lowercase. Hyphenated. | ca, ca-ab |
| _ | Separator | Underscore | |
| 2. Data Source and DGUID | Data Source and DGUID. | Use [data-source-name] for the data source and the DGUID for the geographic area it covers. | city-of-edmonton-2023A00054811061, statcan-2021A000011124 |
| _ | Separator | Underscore | |
| 3. Package | The package name for the dataset (see High-Level Overview). | Lowercase. snake_case allowed for longer titles. | orthoimagery |
| _ | Separator | Underscore | |
| 4. ISO Date | The vintage of the data source. | ISO 8601. Flexible precision. | 2023, 2023-06, 2023-06-01, 2026-02-11T19:50:58 |
| _ | Separator | Underscore | |
| 5. Variant | Resolution or specific subset info. | No Projections. Alphanumeric. Units included. | 075mm, 30cm |
| _ | Separator | Underscore | |
| 6. Version | Semantic Versioning. | v[Major].[Minor].[Patch] | v0.0.1 |
2. Component Detail
A. Source / Location ID (Flexible)
This segment defines the “Who” of the dataset.
- Use the Data Source Name + Hyphen + DGUID.
- Example:
city-of-edmonton-2023A00054811061
- Example:
B. The DGUID (Capitalization Exception)
If using a DGUID (Dissemination Geography Unique Identifier), you must adhere to Statistics Canada standards.
- Link: Statistics Canada: DGUID Definition
- Rule: While the rest of the filename is lowercase, you must capitalize the structural type letter (e.g., ‘A’ for Administrative areas, ‘S’ for Statistical areas) within the DGUID.
- Example:
2021A0005...(Correct) vs2021a0005...(Incorrect).
C. ISO Date Flexibility
Dates follow strictly ISO 8601, but the precision can vary based on the nature of the data (Year, Month, or Day).
- Learn More: Wikipedia: ISO 8601 Date and Time Format
Examples of Date Precision:
- Month Precision:
ca_statcan-2024A000011124_2024-12_v0.0.1.parquet - Day Precision:
ca_statcan-2025A000011124_2025-04-15_v0.0.1.parquet
D. Variant
This field is strictly for resolution (e.g., 075mm, 1m) or content subsets.
- Rule: Do not include projection information (e.g.,
EPSG:3857,NAD83) in the filename. - Reasoning: Projection details are handled exclusively in the file format metadata or the accompanying FAIR Data Catalogue item.
E. Semantic Versioning
We use SemVer (vMAJOR.MINOR.PATCH) to track changes to datasets.
- Link: SemVer.org
| Component | Logic for Data | Example Scenario |
|---|---|---|
| MAJOR | Breaking Change. The schema changed, columns were renamed/removed, or the meaning of the data changed significantly. Old code will break. | v0.0.1 β v1.0.0(Renamed column geo_id to dguid) |
| MINOR | New Feature (Non-Breaking). New columns were added, or coverage was expanded, but old columns remain. Old code still runs. | v0.0.1 β v0.1.0(Added a population_density column) |
| PATCH | Bug Fix. Incorrect data values were fixed, but the schema (columns) is identical. | v0.0.1 β v0.0.2(Fixed typo in metadata or coordinate precision) |
3. Helper Tools
Statistics Canada Geography Search
To accurately populate the DGUID segment of the schema, use this tool to find 2021 Census geographies and their corresponding DGUIDs.
- Tool URL: https://statcan-geography.labs.dataforcanada.org/
- Source Code: GitHub Repository
- Usage: Enter a city or region name to retrieve the correct colloquial name and DGUID pairing (e.g., searching “Ottawa” returns
2021A00053506008).