How the schema works

The structure of the BIDS schema as seen from a top-level file view:

schema
├── BIDS_VERSION
├── SCHEMA_VERSION
├── meta
│   ├── context.yaml
│   └── expression_tests.yaml
├── objects
│   ├── columns.yaml
│   ├── ...
│   └── suffixes.yaml
└── rules
    ├── checks
    ├── ...
    └── tabular_data

The BIDS Schema can be be divided into three major components:

  1. Objects (objects.*)

    • Definitions of BIDS concepts

    • Source of definitions rendered in the specification, for example in the glossary

  2. Rules (rules.*)

    • Validation rules for entity ordering, sidecar values, and both common and modality specific rules
    • Source of filename templates and tables describing sidecar fields and TSV Columns

  3. Meta (meta.*)

    • Defines a "context" object to which rules can be applied
    • Expandable to definitions, tests, or rules related to the schema itself

Note

object dot notation like rules.checks.* is used when referencing parts of the schema throughout this document. Bracket notation such as objects['columns'][*] is equally valid, but more difficult to read._

The character: *, represents a glob and is used to denote matching any string/object_.

Examples of Objects, Rules, and Meta are detailed in the aforementioned linked sections.

Examples are hyperlinked to parts of the schema (source code) where applicable, simply click on the blue links to reach those parts of the schema.

Specific examples from the schema can be expanded or hidden by clicking on blue boxes to show or hide them.

show or hide this example 
this_example:
    - list item 1
    - list item 2