diff --git a/doc/components.rst b/doc/components.rst
index a7925de7..453725f1 100644
--- a/doc/components.rst
+++ b/doc/components.rst
@@ -662,6 +662,32 @@ messages (see above).
 
 .. _XEP-0372 (References): https://xmpp.org/extensions/xep-0372.html
 
+Repeat/Share/Reboost
+~~~~~~~~~~~~~~~~~~~~
+
+The repeat feature (also named "share", or "boost") which consist of republishing an item
+of interest under our own account to make it visible to our subscribers, is done on the
+XMPP side with `XEP-0277 § Repeating a Post`_, and on the AP side it's an ``Announce``
+activity. Conversion is done in both directions and should be transparent to user.
+
+.. _XEP-0277 § Repeating a Post: https://xmpp.org/extensions/xep-0277.html#repeat
+
+Noticed/Like
+~~~~~~~~~~~~
+
+AP's ``Like`` activity is converted on the XMPP side to "`Pubsub Attachment`_", which is
+currently a "protoXEP", i.e. a specification proposed as a standard (not yet reviewed by
+`XMPP Council`_). ``Like`` is converted to ``noticed`` attachment, meaning that it used in
+to indicate that something has been seen and taken into account, without really indication
+if the content is liked or disliked (see Pubsub Attachment § Foreword: `"noticed" instead
+of "like" or "favourite"`_ for the rational).
+
+As usual, conversion is done in both ways.
+
+.. _Pubsub Attachment: https://xmpp.org/extensions/inbox/pubsub-attachments.html
+.. _XMPP Council: https://xmpp.org/about/xmpp-standards-foundation/
+.. _"noticed" instead of "like" or "favourite": https://xmpp.org/extensions/inbox/pubsub-attachments.html#noticed-foreword
+
 Using the Component (for developers)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -686,3 +712,4 @@ Louise can use the following command::
 
 Note the double escaping, one for the shell argument, and the other to specify JSON
 object.
+