These are the bars that every GPA would be just another jacket without - the bare minimum customization necessary.
Queen's Engineering Motto
Quis Dolor Cui Dolium, roughly translated as "Who suffers who has a cask of wine?". This bar goes on the upper right sleeve.
The Queen's crest is placed on the upper right sleeve of the GPA. This is also known as the Pass Crest.
This bar lists your engineering discipline and is worn on the right sleeve below the Queen's Crest. For a list of bars see Discipline Bars.
Please see Year Mottos for a full listing. This bar goes on the upper left sleeve.
This bar goes at the bottom left of the back of the GPA. See Frosh Groups for a list of known frosh groups.
This bar goes at the bottom right of the back of the GPA. It is for the FRECs of a frosh group. See Frosh Groups for a list of known frosh groups.
Flags are sewn onto the back of an engineer's GPA (at the centre of the bottom) to indicate that engineer's heritage/home. Some GPAs also use the flag to indicate the location of a completed exchange/internship.
DISCLAIMER: Keep in mind this is only a rough sketch of a GPA with some basic, non-concrete suggestions of where bars should go. There are no actual rules regarding bar locations, and many choose to place their bars as they please.