> For the complete documentation index, see [llms.txt](https://ess-dive.gitbook.io/file-level-metadata-reporting-format/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ess-dive.gitbook.io/file-level-metadata-reporting-format/csv_dd.md).

# CSV Data Dictionary

## Instructions

1. Create a CSV data dictionary using the [CSV\_dd\_template](https://github.com/ess-dive-workspace/essdive-file-level-metadata/blob/main/CSV_dd/CSV_dd_template.csv). You can create either:\
      a. One data dictionary for each data file or\
      b. One data dictionary representing all data files in your dataset
2. See the [CSV\_dd\_quick\_guide](/file-level-metadata-reporting-format/csv_dd/csv_dd_quick_guide.md) for more details about completing the template
3. Enter a new row in the data dictionary for each column/row name in your data matrix\
      a. Use "\*" wildcard when the description applies to multiple column/row names\
      b. For example - if the same description applies to all spectra data column names in the data file(s)\
            i. one row in the data dictionary can refer to "wave\_\*" and this definition will be understood to apply to multiple column names within a data sheet
4. View an example [CSV\_dd\_example](/file-level-metadata-reporting-format/csv_dd/csv_dd_example.md)
5. Save the CSV\_dd template following the [CSV Reporting Format guidance](https://github.com/ess-dive-workspace/essdive-csv-structure) with the filename "dd.csv" or "\*\_dd.csv". Alternatively you may choose to name you data dictionary:\
      a. With the same name as the associated data file, but include '\_dd.csv' at the end of the file name\
      b. Create a unique filename for your data dictionary\
      c. Incorporate a wildcard into the filename if data dictionary applies to multiple data files (for example - "soil\_cores\_\*\_dd.csv")

**Contents of the CSV\_dd**

For each variable provide the following:

* Column or Row Name
* Unit
* Definition
* Column or Row Long Name
* Data Type
* Missing Value Code

**Notes**

Following the recommended format and structure of the CSV Reporting Format will facilitate File Level Metadata extraction of some fields using the [File Level Metadata Extractor](https://code.ornl.gov/ngee-arctic/ess-dive-meta).