Well I'm gonna take a stab at "placeholder" and no I'm not going to read what wikipedia has to say.
Placeholder, in my world, is like one of those little cards you get with your name on it when you attend a wedding or banquet. The cards are on a table as you enter the facility. You find your name and you place it on the table where you want to sit. Other times, the table number is listed for you. Still, a placeholder holds your place while you mingle with the crowd during cocktail hour. It holds your "place" for the main course/event.
KYS, you overly sensitive snowflake.