regexp matching for flag word

[mayth]

Currently, we can use regexp for the flag word. For example, if the flag word is set to the_[Ff]lags?, these answers will be correct: the_flag, the_flags, the_Flag, the_Flags. This behavior will confuse us but will bring only a little benefit to us.

I suggest that...

1. Disable regexp matching completely (in other words, remove this feature)
2. Disable regexp matching by default, and it can be enabled
3. Enable regexp matching by default, and it can be disabled
4. Enable regexp matching and it cannot be disabled (current behavior)

Any opinion about this?