https://learn.microsoft.com/en-us/dotnet/api/system.web.ui.idatakeyscontrol.clientidrowsuffix?view=netframework-4.8.1
IDataKeysControl.ClientIDRowSuffix Property (System.Web.UI) | Microsoft Learn
Gets the names of the data fields whose values are used to uniquely identify each instance of a data-bound control when ASP.NET generates the ClientID value by...
property systemweb uimicrosoftlearn