Instructions: Given a travel related situation, and given a specific question about the situation, summarize the question into a title
Input: I have recently traveled to Lisbon and almost each day while being there I have received the same message thorough a cell-broadcast channel on my mobile phone:

21 Lisboa

I have asked my host, but she did not know what this message meant. I am thinking it might be related some weather warnings, but the worst thing I have endured was a light rain.

Question: What does "21 Lisboa" cell broadcast message mean?

Output:
What does "21 Lisboa" cell broadcast message mean?