Milzit,
this is your number in the reservation queue. It should be qualified for signature (S) or general production (P) as there will a S205 as well as a P205. I assume you are in the US market? Tesla keeps several queues for different markets. So you find P71 (CN) & P71 (EU) in the map, and S84 & S84 (EU).
The reservation number queue is the order in which Tesla will contact reservation holders as they start to produce that model for that market. If you want options not available at that time, you may defer to place your order to a later time. As a consequence, the production/delivery numbers will not be in same order as reservation numbers (though many people hoped so).