Errata

Remko's biography is outdated. He is no longer the lead developer of the Psi Jabber/XMPP client, but a developer for Swift. The biography at the end of the book is correct.

The two bottom arrows point in the wrong direction.

Chat state transitions are listed differently as the specification does.
http://xmpp.org/extensions/xep-0085.html
From

Note from the Author or Editor:
A transition arrow is missing from the 'Paused' state to the 'Active' state.

I wonder, if the usage of the discovery method "disco#items" is appropriate to perform a query for information about the mentioned weblog, which is a leaf node?

Note from the Author or Editor:
The examples on page 106 use the wrong namespace -- it should be "disco#info" instead of "disco#items. The node type is immaterial here, but we are trying to query for detailed node information, not the items associated with the node. This appears to be a copy-and-paste error.

notify_delete corresponds to node deletion, rather than item deletion.

Note from the Author or Editor:
Correct, notify_delete corresponds to node deletion (and for the purposes of notification, there is no such thing as item "deletion" because that is covered by the notify_retract configuration setting). To fix this errata, we need to change "when an item is deleted" to "when a node is deleted" in the referenced bullet point.

The last sentence says "The content-replace action [...]", which should "The content-remove action [...]".

Note from the Author or Editor:
In the bullet point for the "content-remove" action, the last clause mentions the "content-replace" action but this needs to be corrected to "content-remove".

The Base64-encoded string "AGFsaWNlAHBhc3N3b3JkCg==" in the authentication example should become "AGFsaWNlAHBhc3N3b3Jk".

Page 169 says,

Note from the Author or Editor:
The first sentence of the first paragraph should become:

"Immediately following the notification of succesful authentication, the client resets the session by sending a new stream header, after which the server responds with a new stream header (with a new Stream ID). This time, however, the server announces different stream features:"

Book states: "The only XMPP library for ActionScript is as3xmpp", which is not true as XIFF (http://www.igniterealtime.org/projects/xiff/index.jsp) has been available for many years and it is used in the Sparkweb client which is mentioned in the top of the same page.

Note from the Author or Editor:
The categories for "(Adobe) Flash" and "ActionScript" should be combined in any future edition of the book, since the terms are overlapping because ActionScript is a scripting language for use in the context of the Adobe Flash technology.