Priority Message Indicator (PMI) is a term used for indicating the urgency level of a message or communication. However, the term can be substituted with other phrases such as priority flag, urgent marker, crucial signal, or emergency symbol. These synonyms serve the same purpose as the PMI and enable the receiver to prioritize the message based on its urgency. Other alternative terms include high importance indicator, critical notification, serious notification, vital note, and serious communication marker. Regardless of the term used, it is important for messages with high urgency to be highlighted to ensure that they receive the necessary attention in a timely manner.