The "Grab a Parking Space" application on Kaixin001 (a Chinese social networking site) initially had a parking AJAX call that did not include any additional parameters. Later, they added `a=1`. Then, realizing this was too simple, it was changed to `acc=abc111def`. At first glance, I didn’t investigate deeply enough to figure out where this string came from. Later, I discovered there was actually a function named `acc` that generated this string using a specific algorithm that changed daily:
```javascript
function acc() {
var a = 'abc';
var b = 'def';
return ...
}
```
This function generates a unique string each day based on its internal logic.