# The data dictionary

> Every field of the day files and every LAB column, with its meaning, unit, book and the first session that carries it, grouped by book.

Source: https://firmtape.com/docs/developers/dataset/dictionary

Every field of the day files and every LAB column, with its meaning, unit, book and the first session that carries it, grouped by book.

`/dataset/dictionary`

**This page serves:** [DATASET: The day files and the dictionary](https://firmtape.com/docs/dataset#archive-files), [DATASET: Three books in every file](https://firmtape.com/docs/dataset#three-books). **Plan:** [DATASET](https://firmtape.com/features/dataset). The DATASET licence, monthly or yearly. Reading single sessions on the site stays free.

Read it at [/dataset/dictionary](https://firmtape.com/dataset/dictionary); it is free. The LAB columns, the subset a rule can name, are also served as JSON at `GET /api/lab/vocabulary`.