I stress I don't really know what the string is for
It's the HARDWARE ID, and the problem comes in when the manufacturers change it (even on a driver update), so that the old TV Engine which looks for this name cannot find it in the capturecardsdefinitions.xml
So even with 2 supposedly identical cards they actually may have different ID's from the manufacturer, this is why there are so many posts about this, and you may find in the capturecarddefinitions list identical named cards, with different ID's.
That's why TVE3 is so wonderful.
United Kingdom