Some questions concerning ATK documentation

[Eugene Shatokhin <spectre ispras ru>]

Hello,

Currently I work in the Institute for System Programming of the Russian Academy of Sciences in a project that runs in collaboration with the Linux Foundation (former FSG). 
Our part of the team develops tests for compliance with LSB 3.1 for the atk library.

We have some questions concerning the atk documentation and will appreciate if the atk maintainers could give us comments on this matter. 

The questions below apply to both a non-changing version of the GTK+ 2.6 API documentation and newer GTK+ 2.x API Reference presented at gtk.org.

1. The API reference for some ATK interfaces such as AtkSelection, AtkTable etc. contains sentences like
 "Returns : <...>, or NULL if selection does not implement this interface."
(See atk_selection_ref_selection () for instance.)

What does 'this interface' mean here, AtkSelectionIface or the corresponding method of AtkSelectionIface (ref_selection() for atk_selection_ref_selection())?

If that means AtkSelectionIface, then why is this said in the parameter description:
 "selection :	a GObject instance that implements AtkSelectionIface"?

If 'this interface' means the method of AtkSelectionIface, things get clearer. For example, it explains the behaviour of atk_selection_ref_selection() when we pass an AtkNoOpObject to it (or some other implementation of AtkSelectionIface with NULL in the ref_selection field of the virtual function table).

2. If a function like atk_table_ref_at() gives us a pointer to some atk object, should we call g_object_unref for it when it is no longer needer? Or, perhaps, this depends on the actual implementation of AtkTable and is not always mandatory?

3. This is possibly a misprint:
In AtkAction reference one can see 
 "i :	the action index corresponding to the action to be performed"
in the descriptions of these functions:

atk_action_get_description, 
atk_action_get_name,
atk_action_get_localized_name,
atk_action_get_keybinding,
atk_action_set_description

while the words "to be performed" apply to atk_action_do_action.
(Perhaps, it is due to copy & paste.)

With best regards,
Eugene Shatokhin

ISP RAS
www.ispras.ru