Since I started this, I guess I need to also state for the record that I'm not a dimwit, either. I know what happens to symmetrical-cored balls, post-drilling. I would think 99 percent of the members of a site dedicated to bowling ball technology would, too.
For that matter, try this one: Take a symmetrical-cored ball, and DON'T drill it. Turn it 45 degrees and roll it granny-style, and the attitude it presents toward the lane itself will be assymetric (unless it finds its way back to its two primary axes). The only way a ball truly rolls "symmetrically" is if it is orientated squarely on its X and Y axes.
The use of "assym" versus "sym" implies terminology most of us probably understand by now and just saves keystrokes.
And, as someone else mentioned, I really would hope you wouldn't laugh at me if I used these shortcut terms in your presence at your shop. You can ask the management at my previous shop, Bowler's Advantage in Smyrna, Tenn., if I'm a good customer. No telling how many thousands I spent in that place -- partially because there was mutual respect between driller(s) and customer. It also explains a good bit of the reason that, since I moved to a new area and had a very bad experience with my local shop over a separate customer service issue, I'll probably be drilling my own stuff within the year. Just some friendly customer advice, there.
Jess