diff --git a/man/sd_bus_call.xml b/man/sd_bus_call.xml
index b93efb2622..f47f9c8526 100644
--- a/man/sd_bus_call.xml
+++ b/man/sd_bus_call.xml
@@ -61,32 +61,33 @@
received a D-Bus error reply), ret_error is initialized to an instance of
sd_bus_error describing the error.
- sd_bus_call_async() is like sd_bus_call() but
- works asynchronously. The callback indicates the function to call when
- the response arrives. The userdata pointer will be passed to the callback
- function, and may be chosen freely by the caller. If slot is not
- NULL and sd_bus_call_async() succeeds,
- slot is set to a slot object which can be used to cancel the method call
- at a later time using
+ sd_bus_call_async() is like sd_bus_call() but works
+ asynchronously. The callback indicates the function to call when the response
+ arrives. The userdata pointer will be passed to the callback function, and may be
+ chosen freely by the caller. If slot is not NULL and
+ sd_bus_call_async() succeeds, slot is set to a slot object
+ which can be used to cancel the method call at a later time using
sd_bus_slot_unref3.
- If slot is NULL, the lifetime of the method call is
- bound to the lifetime of the bus object itself, and it cannot be cancelled independently. See
+ If slot is NULL, the lifetime of the method call is bound to
+ the lifetime of the bus object itself, and it cannot be cancelled independently. See
sd_bus_slot_set_floating3
for details. callback is called when a reply arrives with the reply,
- userdata and an sd_bus_error output
- parameter as its arguments. Unlike sd_bus_call(), the
- sd_bus_error output parameter passed to the callback will be empty. To
- determine whether the method call succeeded, use
+ userdata and an sd_bus_error output parameter as its
+ arguments. Unlike sd_bus_call(), the sd_bus_error output
+ parameter passed to the callback will be empty. To determine whether the method call succeeded, use
sd_bus_message_is_method_error3
on the reply message passed to the callback instead. If the callback returns zero and the
- sd_bus_error output parameter is still empty when the callback
- inishes, other handlers registered with functions such as
+ sd_bus_error output parameter is still empty when the callback finishes, other
+ handlers registered with functions such as
sd_bus_add_filter3 or
- sd_bus_add_match3
- are given a chance to process the message. If the callback returns a non-zero value or the
- sd_bus_error output parameter is not empty when the callback finishes,
- no further processing of the message is done. Generally, you want to return zero from the
- callback to give other registered handlers a chance to process the reply as well.
+ sd_bus_add_match3 are
+ given a chance to process the message. If the callback returns a non-zero value or the
+ sd_bus_error output parameter is not empty when the callback finishes, no
+ further processing of the message is done. Generally, you want to return zero from the callback to give
+ other registered handlers a chance to process the reply as well. (Note that the
+ sd_bus_error parameter is an output parameter of the callback function, not an
+ input parameter; it can be used to propagate errors from the callback handler, it will not receive any
+ error that was received as method reply.)
If usec is zero, the default D-Bus method call timeout is used. See
sd_bus_get_method_call_timeout3.