Table 1.

Definitions for BIDS-related terms.

Term	Definition
Data type	A functional group of different types of data. Data files are stored in a folder named for the specific data type (e.g., anat, func, fmap, etc).
Suffix	The category of brain data recorded by a file. Often referred to as the “modality”, it is a sub-categorization of the data type (e.g., epi is a suffix of the fmap data type). The suffix may overlap, but should not be confused with the data type.
Entity	Label(s) that helps differentiate the data, based on image parameters (e.g., acq, dir, etc). Only specific entity labels are allowed for certain data type and suffix data, and the ordering of entity labels is necessary for BIDS compliance.
Series ID	Unique value given to images based on specific metadata (SeriesDescription, ImageType, RepetitionTime, and EchoTime; see Fig. 2b).
Task events timing files	Files describing timing and other properties of events recorded during a run. For non-rest task functional BOLD images, BIDS highly recommends that such files be formatted as events.tsv files, containing standard information such as stimulus onset, duration, etc.
Validation errors (i.e., bids-validator errors)	Situations in which an entry is not compliant with BIDS specification. Examples include improper entity label(s), misordering of entity labels, use of special characters, etc. Errors must be addressed to ensure BIDS-compliant data.
Validation warnings (additional ezBIDS- specific guidance messages and information)	Situations in which some aspect of the data might be improper and worth addressing. Examples may include alerting users to exclude a sequence (e.g., events.tsv) from BIDS conversion because a corresponding sequence (functional BOLD) has been excluded. Warnings are meant to ensure improved quality of the dataset for curation purposes; however, they do not need to be addressed in order to create a BIDS-compliant dataset.

The terms data type, suffix, entity, and task events timing files come directly from the BIDS specification.