diff --git a/README.md b/README.md
index f93c3e95..b28a4f4d 100644
--- a/README.md
+++ b/README.md
@@ -11,8 +11,8 @@ It is an independent open source implementation that is not affiliated with or e
## Features
* Fully [RFC 8555](https://tools.ietf.org/html/rfc8555) compliant
-* Supports the `http-01`, `dns-01` and `tls-alpn-01` challenges
-* Supports the [acme-ip draft](https://tools.ietf.org/html/draft-ietf-acme-ip)
+* Supports the `http-01`, `dns-01`, and `tls-alpn-01` ([RFC 8737](https://tools.ietf.org/html/rfc8737)) challenges
+* Also supports [RFC 8738](https://tools.ietf.org/html/rfc8738) IP identifier validation
* Supports the [acme-star draft](https://tools.ietf.org/html/draft-ietf-acme-star) for short-term automatic certificate renewal (experimental)
* Easy to use Java API
* Requires JRE 8 (update 101) or higher
diff --git a/acme4j-client/src/main/java/org/shredzone/acme4j/Identifier.java b/acme4j-client/src/main/java/org/shredzone/acme4j/Identifier.java
index 8bd11db8..ceee5a0d 100644
--- a/acme4j-client/src/main/java/org/shredzone/acme4j/Identifier.java
+++ b/acme4j-client/src/main/java/org/shredzone/acme4j/Identifier.java
@@ -51,7 +51,7 @@ public class Identifier implements Serializable {
/**
* Type constant for IP identifiers.
*
- * @see draft-ietf-acme-ip
+ * @see RFC 8738
*/
public static final String TYPE_IP = "ip";
diff --git a/src/doc/docs/challenge/tls-alpn-01.md b/src/doc/docs/challenge/tls-alpn-01.md
index 6a6100c8..7b051f0c 100644
--- a/src/doc/docs/challenge/tls-alpn-01.md
+++ b/src/doc/docs/challenge/tls-alpn-01.md
@@ -1,9 +1,6 @@
# tls-alpn-01 Challenge
-With the `tls-alpn-01` challenge, you prove to the CA that you are able to control the web server of the domain to be authorized, by letting it respond to a request with a specific self-signed cert utilizing the ALPN extension.
-
-!!! note
- This challenge is not part of the ACME specifications. It is specified [in a separate IETF document](https://tools.ietf.org/html/draft-ietf-acme-tls-alpn) and is still work in progress.
+With the `tls-alpn-01` challenge, you prove to the CA that you are able to control the web server of the domain to be authorized, by letting it respond to a request with a specific self-signed cert utilizing the ALPN extension. This challenge is specified in [RFC 8737](https://tools.ietf.org/html/rfc8737).
`TlsAlpn01Challenge` provides a byte array called `acmeValidation`:
diff --git a/src/doc/docs/index.md b/src/doc/docs/index.md
index 754f00ea..947563f6 100644
--- a/src/doc/docs/index.md
+++ b/src/doc/docs/index.md
@@ -15,8 +15,8 @@ Latest version:  compliant
-* Supports the `http-01`, `dns-01` and `tls-alpn-01` challenges
-* Supports the [acme-ip draft](https://tools.ietf.org/html/draft-ietf-acme-ip)
+* Supports the `http-01`, `dns-01`, and `tls-alpn-01` ([RFC 8737](https://tools.ietf.org/html/rfc8737)) challenges
+* Also supports [RFC 8738](https://tools.ietf.org/html/rfc8738) IP identifier validation
* Supports the [acme-star draft](https://tools.ietf.org/html/draft-ietf-acme-star) for short-term automatic certificate renewal (experimental)
* Easy to use Java API
* Requires JRE 8 (update 101) or higher
diff --git a/src/doc/docs/usage/order.md b/src/doc/docs/usage/order.md
index 07a597ed..0055aa53 100644
--- a/src/doc/docs/usage/order.md
+++ b/src/doc/docs/usage/order.md
@@ -168,7 +168,7 @@ auth.deactivate();
## Use IP Identifiers
-_acme4j_ supports the [ACME IP](https://tools.ietf.org/html/draft-ietf-acme-ip) extension. It permits validation of IP addresses instead of domain names. If your CA offers ACME IP support, you can add IP `Identifier` objects to the order:
+_acme4j_ supports IP identifier validation, as specified in [RFC 8738](https://tools.ietf.org/html/rfc8738). It permits validation of IP addresses instead of domain names. If your CA offers ACME IP support, you can add IP `Identifier` objects to the order:
```java
Order order = account.newOrder()