What Is this little blue arrow

[ParmJaiya]

Hi, I attached a screen shot can you please tell me how to add this little arrow in the timeline which says help red monster at the top of all layers. 

Thank you 

 

[Jeff Almasol · Accepted solution]

Use the Timeline > Add Marker or Timeline > Add Stop Marker menu command. A stop marker allows playback to stop when the playhead reaches it.

To rename a marker, double-click it.