# Naming Requirements and Restrictions for Treasure Data Entities

Treasure Data limits how you name entities, and the number of characters you can use in entities.

See [Upper Limits (MAX)](/requirements-and-limitations/list-of-upper-limits-max-on-treasure-data) for size and volume limits on Treasure Data entities.

Name rules exist for:

* [Tables and Databases](#tables-and-databases)
* [Columns](#columns)
* [Passwords](#passwords)
* [Names for Users, Policies, and Permissions](#names-for-users-policies-and-permissions)
* [TD Workflows](#td-workflows)


## Tables and Databases

Name rules for tables and databases are as follows:

* only lower case letters, numbers, and the _ (underscore)
* 3 and 128 characters long


## Columns

Name rules for columns are as follows:

* only lower case letters, numbers, the _ (underscore)
* cannot begin with a number, for example: `0422col` is not an acceptable column name


If an illegal column name is detected, a system alias is generated. You can use this alias to query or change this column to another acceptable column name, if you want to.

## Passwords

The TD account owner or administrator [specifies password criteria](/products/control-panel/security/sign-in-settings/specifying-the-account-password-policy).

The general, default rules for user passwords are as follows:

* 8-128 characters long
* consists of Basic Latin (ASCII) characters


For a list of Basic Latin (ASCII) characters, go to the [Library of Congress Basic Latin (ASCII) Code Table](http://lcweb2.loc.gov/diglib/codetables/42.md).

## Names for Users, Policies, and Permissions

User and Policy names must be Unicode characters and can include a symbol, control characters, emoji, whitespace, up to 255 characters.

## TD Workflows

Name rules for projects and workflows are as follows:

* Project/workflow name cannot start with **a number** or `/`
* Project/workflow name cannot contain any of the following: `+, ^ , @, \\. :, *, ?, ", <, >, |, &, <space>`