How to add new ribbon tab? is it only to add my button on existing tabs(home, voice, custom etc.)?
is there any documents for ASRibbonPlugin API?

The details are updated in the SDK Document available on this forum. New chapter added about adding buttons to Ribbon UI.

thank you for your answer. but there is only to add buttons on 'Custom' tab.
the sample is below.
customRibbonTab = Singleton.GUIHostPlugin.GetRibbonTab(enTab.Custom)

I want to create new tab, for example 'outbound' tab. is it possible? or can change the custom tab label string?

Hi Expert,

where I can check the size of largeImageSource and smallImageSource?

public RibbonItem(string name, RibbonItemType type, string label, string header, BitmapImage smallImageSource, BitmapImage largeImageSource, string toolTip, string keyTip, bool isVisible, EventHandler click, EventHandler dropdownOpened, EventHandler dropdownClosed, ToolStripItem toolStripItem)