Right now the default text in Magento StackExchange reads poorly:
What's your the Magento e-Commerce platform question? Be specific.
How can this be edited?
Good point! Now it says
What's your Magento question? Be specific.
To answer the question you actually asked, this is a setting that can be changed only by someone with dev access. It's an easy change, you just need to get the right person's attention. That's hard to do directly, so your best bet is to post on meta and wait for a CM like me to see it... and possibly bug your mods about it and have them poke me if I get distracted thinking about Winter Bash and drop the ball on responding to meta... not that that would ever happen....