I do apologize for the confusion factor, shall we quantify terms...
‘There are a few different types of holster retention...
Most common is the thumb break, employing a strap, leather or nylon in most cases,
A more recent invention is the trigger guard lock. Trigger guard lock holsters employ a locking mechanism...
holster actually retains a firearm is by clamping down on a gunhough though perhaps a better noun should be devised for them than retention holsters which
have a device that more strenuously holds a firearm in place than the typical holster”
Paraphrased from
http://gunbelts.com/blog/do-i-need-a-retention-holster-for-open-carry/
Now as i was saying...non-retention, meaning no strap, no fancy trigger guard, or any device...just good tight fitting leather holster made for that specific firearm, with trigger covered, [not a generic ‘for J frame’ or ‘compact’ or ‘1911 style’ written on the packaging] holding my SD polymer or compact FN, or wittle shield firearm in place by ‘friction’ .