diff --git a/content/references/xrp-ledger-toml.md b/content/references/xrp-ledger-toml.md
index 5024f237a3..e616f39ae1 100644
--- a/content/references/xrp-ledger-toml.md
+++ b/content/references/xrp-ledger-toml.md
@@ -169,6 +169,7 @@ For _each_ `[[VALIDATORS]]` entry, you MAY provide any of the following fields:
 | Field        | Type   | Description                                          |
 |:-------------|:-------|:-----------------------------------------------------|
 | `public_key` | String | The master public key of your primary validator, encoded in the XRP Ledger's base58 format (typically, this starts with `n`). |
+| `attestation`| String | The signed attestation message that is output by the `set_domain` command in the [validator-keys-tool](https://github.com/ripple/validator-keys-tool)
 | `network`  | String | Which network chain this validator follows. If omitted, clients SHOULD assume that the validator follows the production XRP Ledger. Use `main` to explicitly specify the production XRP Ledger. Use `testnet` for Ripple's XRP Ledger Test Net. You MAY provide other values to describe other test nets or non-standard network chains. |
 | `owner_country` | String | The two-letter ISO-3166-2 country code describing the main legal jurisdiction that you (the validator's owner) are subject to. |
 | `server_country` | String | The two-letter ISO-3166-2 country code describing the physical location where this validating server is. |