I'm going to learn about the regexes, and I want to know where in CT I can use them.
I think I can use them in:
Masato: I want to know where in CT I can use them
A question worth an extensive KB entry, and not only where, but
>> A question worth an extensive KB entry
I didn't expect that this is such a big theme. But, anyway, I hope to discover those things one by one.
Masato: I didn't expect that this is such a big theme
I think it is, because a lot of attention has been paid to it previously, and regexes are both useful and powerful, and dangerous.
Okay, I'd suggest you consult http://www.regular-expressions.info/index.html (buy the PDF version, because you're going to need it all the time), and pay special attention to the Java flavour. Use http://regexr.com to test your regexes extensively. There's even an app version you can download for free.