---
title: Field types
description: 'What a table''s field may be: the closed set of types a submitted value
  is checked against, the roles the platform reads a field for, and what a listing
  may narrow and order rows by.'
sidebar:
  order: 19
---

What a table's field may be: the closed set of types a submitted value is checked against, the roles the platform reads a field for, and what a listing may narrow and order rows by. Served over MCP as `vizitka://docs/fields`, and by `describe_vocabulary` with `topic=fields`.

## Types

What a field holds, and what a filter may ask of it.

| Type | What a row holds | A filter asks | May be filterable | May be sortable |
| --- | --- | --- | --- | --- |
| `text` | One line of text. | `==`, `!=`, `<`, `<=`, `>`, `>=`, `includes`, `startsWith` | yes | yes |
| `long_text` | Several lines of text. | `includes`, `startsWith` | yes | no |
| `markdown` | A document, written in Markdown. A page reads it as a text, and draws it with `markdown`. | `includes`, `startsWith` | yes | no |
| `email` | An email address. | `==`, `!=`, `<`, `<=`, `>`, `>=`, `includes`, `startsWith` | yes | yes |
| `phone` | A phone number. | `==`, `!=`, `<`, `<=`, `>`, `>=`, `includes`, `startsWith` | yes | yes |
| `url` | A web address. | `==`, `!=`, `<`, `<=`, `>`, `>=`, `includes`, `startsWith` | yes | yes |
| `number` | A number. | `==`, `!=`, `<`, `<=`, `>`, `>=` | yes | yes |
| `date` | A calendar date. A host answers it as the text `YYYY-MM-DD`, and a page reads it as a date. | `==`, `!=`, `<`, `<=`, `>`, `>=` | yes | yes |
| `datetime` | A day and a time of that day, in UTC, to the millisecond. A host answers it as the text `YYYY-MM-DDTHH:MM:SS.mmmZ`, and a page reads it as a time. | `==`, `!=`, `<`, `<=`, `>`, `>=` | yes | yes |
| `boolean` | `true` or `false`. | `==`, `!=`, and a field of it stands alone as `p.field` or `!p.field` | yes | no |
| `choice` | One of the field's options. | `==`, `!=`, `<`, `<=`, `>`, `>=`, `includes`, `startsWith` | yes | yes |
| `choice` with `multiple: true` | A list of the field's options. | `includes` | yes | no |
| `reference` | One row of another table. A page reads the field as that row. | `==`, `!=` | yes | no |
| `references` | Several rows of another table. A page reads the field as the list of those rows. | `includes` | yes | no |
| `picture` | One picture among the site's files. | nothing | no | no |

## Roles

What the platform itself reads a field for, said on the field with `role`. One field per role, and a table that names none for a role falls back to the field literally called that.

| Role | What reads it | Played by |
| --- | --- | --- |
| `title` | What the row is called: the title of its own page and of a shared link, its name wherever rows are listed, and what its address is made from when it is given none. | `text`, `long_text`, `markdown`, `email`, `phone`, `url`, `number`, `date`, `datetime`, `boolean`, `choice` |
| `body` | What the row says. | `text`, `long_text`, `markdown`, `email`, `phone`, `url`, `number`, `date`, `datetime`, `boolean`, `choice` |
| `language` | Which language the row is written in. | `text`, `long_text`, `markdown`, `email`, `phone`, `url`, `number`, `date`, `datetime`, `boolean`, `choice` |
| `summary` | What the row is about in a sentence or two: the description its own page gives a search engine or a shared link. | `text`, `long_text`, `markdown`, `email`, `phone`, `url`, `number`, `date`, `datetime`, `boolean`, `choice` |
| `cover` | The row's picture: what a shared link of its own page shows. | `picture` |

## Listings

**500 rows at most in one read.** How many rows one load may read. A bare `:for` over `tables.posts` walks at most this many, newest first, and so does one page of a listing asked to be bigger than it. `paginate` is how a page reaches the rest, because a page is read in the query and every row a table holds is on one.

### Comparisons

What a filter may compare a value with. Which of them a field answers to is its own type's.

| Comparison | What it means |
| --- | --- |
| `is` | Equal to this value. |
| `is_not` | Anything but this value, and a row that never carried the field counts. |
| `from` | This value or after it, in the order its own type sorts in. |
| `until` | Before this value and not equal to it, so two ranges meet without overlapping. |
| `ilike` | Has this text somewhere inside it, ignoring case. |
| `starts_with` | Begins with this text, ignoring case. |
| `includes` | Holds this value among the several it lists. Only on a field marked `multiple`, and on a `references` field, which is asked about a row. |

### Directions

Which way an order reads a listing. A field can be ordered on when its own definition marks it `sortable`, which is a separate question from `filterable`.

| Direction | What it means |
| --- | --- |
| `asc` | Smallest first: A before Z, the oldest date, the cheapest price. |
| `desc` | Largest first: Z before A, the newest date, the dearest price. |

## Disk pictures in a markdown body

`::image[Alt text]{key=<key>}`, on a line of its own, with any of these pairs after the key. Keys in the order the editor writes them, each with the values it accepts. Absent is the default: a picture on its own line, at the full width of the article.

| Key | Values |
| --- | --- |
| `align` | `left`, `center`, `right` |
| `size` | `small`, `medium`, `large` |