This page describes rich text formatting for the Entities API (for example, fields.description on a feature). The Entities API enforces a strict HTML whitelist: any unsupported tag results in a 400 response.

When sending rich text to the Entities API:

Always wrap content in a tag (e.g. <p>text</p>). Plain text is not accepted.
Use only the tags listed in the table below.
Close every tag, including void elements (<br/>, <hr/>).
Quote all attribute values.

📘
Notes API uses different rules
Feedback (notes) can arrive from many sources and is read-only in the UI, so the Notes API strips visual styling and keeps only semantic tags rather than rejecting input.

Tag	Description
`<h1>, <h2>`	Headers
`<p>`	Paragraph
`<b>`	Bold
`<i>`	Italics
`<u>`	Underline
`<code>`	`Code`
`<ul>`	Unordered list
`<ol>`	Ordered list
`<li>`	List item
`<a>`	Link
`<hr/>`	Horizontal line
`<pre>`	Code block
`<blockquote>`	Block quote
`<s>`	~~Strikethrough~~