# series An array of series. Basic series information is stored in the main `squirrel.json` file. Extended information including series parameters such as DICOM tags are stored in a `params.json` file in the series directory.

### JSON variables :blue\_circle: Primary key\ :red\_circle: Required\ :yellow\_circle: Computed (squirrel writer/reader should handle these variables)

Variable	Type	Default	Description
`BidsEntity`	string		BIDS entity (anat, fmri, dwi, etc)
`BidsSuffix`	string		BIDS suffix
`BIDSTask`	string		BIDS Task name
`BIDSRun`	number		BIDS run number
`BIDSPhaseEncodingDirection`	string		BIDS PE direction
`Description`	string		Description of the series
`ExperimentName`	string		Experiment name associated with this series. Experiments link to the experiments section of the squirrel package
`Protocol`	string	🔴	Protocol name
`Run`	number		The run identifies order of acquisition in cases of multiple identical series.
`SeriesDatetime`	date	🔴	Date of the series, usually taken from the DICOM header
`SeriesNumber`	number	🔴 🔵	Series number. May be sequential, correspond to NiDB assigned series number, or taken from DICOM header
`SeriesUID`	string		From the SeriesUID DICOM tag
`BehavioralFileCount`	number	🟡	Total number of beh files (including files in subdirs)
`BehavioralSize`	number	🟡	Size of beh data, in bytes
`FileCount`	number	🟡	Total number of files (including files in subdirs)
`Size`	number	🟡	Size of the data, in bytes
params	JSON file		`data/subjectID/studyNum/seriesNum/params.json`
analysis	JSON object

### Directory structure Files associated with this section are stored in the following directory. `subjectID`, `studyNum`, `seriesNum` are the actual subject ID, study number, and series number. For example `/data/S1234ABC/1/1`. > `/data///` Behavioral data is stored in > `/data////beh` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.neuroinfodb.org/nidb/contribute/squirrel-data-sharing-format/specification-v1.0/data/subjects/studies/series.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.