? about event commmand names

Alright heres another one of my probably really simple questions that i dont know lol.... well I'm making a blacksmith system in my game... and im getting help from a tutorial on gamingw.net but on the website it gives the code you know like show choices and so on.... but one of the choices is branch... and i know it means to check whether you have the required item or not but i dont no which event command it is. lol

Attached below:

Thanks for the help