Delegate Controls
Applies to: SharePoint 2016 | SharePoint Foundation 2013 | SharePoint Online | SharePoint Server 2013
Delegate controls provide a means to specify candidate controls for a particular functionality and to choose a functionality provider for those controls.
Example
The following example specifies a control and tool tips to implement for the input box of the search area in SharePoint pages.
<?xml version="1.0" encoding="utf-8" ?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
<Control
Id="SmallSearchInputBox"
Sequence="100"
ControlSrc="~/_controltemplates/searcharea.ascx">
<Property Name="SearchTextToolTip">Search this site</Property>
<Property Name="SearchImageToolTip">Go</Property>
</Control>
</Elements>