What does a hash key look like on a phone?

Excuse me, could you please elaborate on what a hash key looks like specifically when it's displayed on a phone? I'm curious about its format, length, and whether it's easily recognizable for the average user. Additionally, is there a standard way it's presented across different mobile devices or platforms? Lastly, are there any security measures or precautions users should be aware of when dealing with hash keys on their phones?