# data-dictionary The data-dictionary object stores information describing mappings or any other descriptive information about the data. This can also contain any information that doesn't fit elsewhere in the squirrel package, such as project descriptions. Examples include mapping numeric values (1,2,3,...) to descriptions (F, M, O, ...)

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

Variable	Type	Default	Description
`DataDictionaryName`	string	🔴	Name of this data dictionary.
`NumFiles`	number	🟡	Number of files contained in the experiment.
`Size`	number	🟡	Size, in bytes, of the experiment files.
`VirtualPath`	string	🟡	Path to the data-dictionary within the squirrel package.
data-dictionary-item	JSON array		Array of data dictionary items. See next table.

***data-dictionary-item***

Variable	Type	Default	Description
`VariableType`	string	🔴	Type of variable.
`VariableName`	string	🔴 🔵	Name of the variable.
`Description`	string		Description of the variable.
`KeyValueMapping`	string		List of possible key/value mappings in the format `key1=value1, key2=value2`. Example `1=Female, 2=Male`
`ExpectedTimepoints`	number		Number of expected timepoints. Example, the study is expected to have 5 records of a variable.
`RangeLow`	number		For numeric values, the lower limit.
`RangeHigh`	number		For numeric values, the upper limit.

### Directory structure Files associated with this section are stored in the following directory. > `/data-dictionary` --- # 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-dictionary.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.