Insider jargon, previously known as cant, is designed to keep outsiders out.
The burglars in cartoons are often seen wearing a black mask over their eyes (like Robin in Batman but for a different reason) and carrying a bulging sack over their shoulders.
[Of course, the burglar’s sack was rarely bulging. A robber would have to have the perfect haul to get the right mix of value, density and weight. You can’t fit a chest of drawers in the sack, and that much gold would be impossible to carry. But I digress.]
The cant for this was ‘swag’, which comes from an old term for swaying or bulging. Sort of wishful thinking.
And thus we get to the swag of business promo and conference loot…
Establishing jargon is a key step in group identity. It’s rarely dictated from the top down, but permitting and celebrating it is a smart move if you’re looking for group cohesion.