The use of acronyms in many disciplines, particularly in today's digital world, is large, and the knowledge behind each acronym is sometimes taken for granted. For example, common acronyms such as GPS, LCD, LED, SIM, Wi-Fi, PDF, HDMI, MPEG, IP, or HTML are used without considering what is behind each letter. The reality is that they are all acronyms. This work proposes an inverted classroom activity in the course Architecture and Telematic Networks of the Bachelor's Degree in Telecommunication Engineering at the Escuela Politécnica Superior de Gandia of the Polytechnic University of Valencia, Spain. In this activity, once a week, the students, in groups of two or three people, must expose to the rest of their classmates through an elevator pitch the hidden meaning behind each acronym used in the contents of the subject. The acronyms in this course are more cryptic (ARP, ICMP, DHCP, NAT...), and in the end, their thoughtless use can be more of a problem than a help to understand the topic. So, this activity addresses two problems. First, they strive to understand what lies behind each acronym collectively, and second, they acquire the knowledge they will need for their professional careers in the future. In short, this classroom experience has demonstrated that providing a vital glossary of the course helps the students to delve into purely theoretical concepts differently and engagingly.
