Architecting and designing
  
Rectangular symbol
A rectangular symbol on a diagram can take many shapes. In addition to being a rectangle, the symbol may be elliptical, circular, and even shaped like a cloud.
The three circles in the top-left corner of a symbol are placed automatically by System Architect.
The left circle is filled in when a Comment Command, Dictionary Menu is added to the symbol.
The middle circle is filled in when a symbol has a child diagram (see Creating child diagrams and attaching them to symbols).
There is no current significance to the right circle.