Centenary taverns in Madrid

I propose a trip to the past, visiting those old taverns, now centuries old, where we will discover what the measure of a flat of wine is, which is a fifteen of morapio that appears so much in Valle Inclán's work, Luces de Bohemia; because we ordered a beer, how the tapa came about, both the food and the name, or because many taverns went to others to "steal" the shells of the shrimp that were lying on the floor, among many other things.
The visit will begin in the place where the Madrid taverns arose, and we will learn about the curious rules by which they had to be governed for years.