> ## Documentation Index
> Fetch the complete documentation index at: https://cloudinary.com/documentation/llms.txt
> Use this file to discover all available pages before exploring further.

# Permitted naming conventions



> **NOTE**: These requirements may change from time to time due to different design requirements.

## Cloud name

- Length: between 2 and 128 characters
- Allowed characters: a-z, A-Z, 0-9, -
- Must begin with a letter
- Must not end with "-cld" unless using a [private S3 bucket](backups_and_version_management#using_your_own_backup_storage)

## Public ID

- Length: between 1 and 255 characters
- Allowed characters: any language character (including non-English) and in addition dot `.` and dash `-`, as well as any HTML escaped characters (E.g. `%26` as opposed to `&`). While `?&#\%<>+` are utterly forbidden, other special characters will be replaced with underscores `_` and preceding/trailing occurrences will be trimmed off
- Shouldn't begin nor end with whitespace or forward-slash (those will be omitted as well)
- You can't use 'v' followed by numeric characters as the name of a folder.

> **READING**:
>
> * [public_id parameter](image_upload_api_reference#upload_optional_parameters): The Upload API reference for the `public_id` parameter, including current rules for character set, length, file extensions, and `image`/`video`/`raw` asset types.

> * [When might underscores in public IDs or folder names cause errors?](ts_why_shouldnt_i_use_underscore_within_folder_names): Companion guidance on naming pitfalls when public IDs contain underscores and slashes.